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GIFT    OF 


Class 


DEPARTMENT  OF  COMM  D  LABOR 


GEORGE    M.   BOWERS.    Commissioner 


THE  PHOTOGRAPHY  OF  AQUATIC  ANIMALS  IN  THEIR 
NATURAL  ENVIRONMENT 


FROM  BULLETIN  OF  THE  BUREAU  OF  FISHERIES 


>F  FISHERIES  DC- 


DEPARTMENT  OF  COMMERCE  AND  LABOR 
BUREAU  OF  FISHERIES 

GEORGE    M.   BOWERS.    Commissioner 


THE  PHOTOGRAPHY  OF  AQUATIC  ANIMALS  IN  THEIR 
NATURAL  ENVIRONMENT 


FROM  BULLETIN  OF  THE  BUREAU  OF  FISHERIES 
Volume  XXVII,  1907,  Pages  41  to  68,  Plates  H  to  V 


BUREAU  OF  FISHERIES  DOCUMENT  NO.  635 
ISSUED  AUGUST  22  1908 


WASHINGTON 

GOVERNMENT    PRINTING    OFFICE 
1908 


THE  PHOTOGRAPHY  OF  AQUATIC  ANIMALS  IN  THEIR  NATURAL 

ENVIRONMENT 


By  JACOB  REIGHARD 

Professor  of  Zoology,  University  of  Michigan 


BUREAU  OF  FISHERIES  DOCUMENT  NO.  635 

41 


174289 


CONTENTS. 


Page. 

Introduction : 43 

Principles  of  photography  of  submerged  objects, 43 

A  new  method  of  photographing  submerged  objects  with  camera  above  the  surface 40 

Previous  attempts  to  photograph  submerged  objects  by  means  of  a  submerged  camera 51 

Boutan's  first  apparatus 51 

Boutan's  second  apparatus 54 

Boutan's  third  apparatus 54 

Boutan's  methods  of  artificial  illumination 57 

Bristol's  subaquatic  camera 59 

A  new  subaquatic  apparatus 00 

The  camera CO 

The  water-tight  box ^ 62 

Using  the  apparatus C3 

Some  limitations  of  subaquatic  photography 06 

Literature  cited 68 

42 


PHOTOGRAPHS  TAKEN  WITH  CAMERA  SUBMERGED. 


THE  PHOTOGRAPHY  OF  AQUATIC  ANIMALS  IN  THEIR  NATURAL  ENVIRONMENT. 


BY  JACOB  REIGHARD, 
Professor  of  Zoology,  University  of  Michigan. 


INTRODUCTION. 

Many  things  have  contributed  in  recent  years  to  extend  the  use  of  photography 
into  fields  of  natural  history  not  previously  occupied  by  it.  Dry  plates  and  films 
have  been  made  more  rapid  and,  with  the  advent  of  the  nonhalation  and  orthochro- 
matic  sorts,  have  been  adapted  to  every  use;  with  new  sorts  of  optical  glass  it  has 
been  possible  to  construct  photographic  lenses  of  great  speed;  cameras  and  acces- 
sories have  been  made  portable  and  suited  to  a  variety  of  needs.  As  a  result  we 
find  in  scientific  publications,  as  well  as  in  more  popular  books  and  periodicals, 
excellent  photographs  of  living  animals  and  plants  in  their  natural  environment. 
Students  and  lovers  of  birds,  field  naturalists  and  hunters  of  big  game  have  all 
contributed  their  part.  Birds  have  been  photographed  on  the  wing  and  while 
engaged  in  their  domestic  duties,  on  the  nest  in  almost  inaccessible  high  trees, 
on  mountain  crags,  and  on  the  faces  of  cliffs.  Mammals  have  been  photographed 
in  nature  under  a  great  variety  of  conditions.  Reptiles,  amphibians,  insects — 
everv  variety  of  terrestrial  animal  has  been  pictured  by  the  lens. 

Quite  in  contrast  has  been  the  limited  use  of  photography  for  aquatic  organisms. 
Shufeldt  (1898),  Dugmore  (Jordan  &  Evermann,  1902),  Saville-Kent  (1893),  Fabre- 
Domergue  (1898),  have  from  time  to  time  succeeded  in  making  excellent  photo- 
graphs of  animals  in  aquaria  under  more  or  less  artificial  conditions,  but  the  work 
has  been  carried  scarcely  beyond  this  (see  Boutan,  1893,  1898,  1898a,  1900,  and 
Rudaux,  1908).  The  present  paper  deals  rather  with  the  photography  of  aquatic 
organisms,  not  merely  in  their  native  element,  but  in  their  native  environment  and 
under  normal  conditions.  It  attempts  to  show  how  they  may  be  photographed, 
not  by  taking  them  from  their  native  haunts  and  placing  them  in  artificial  containers, 
but  by  carrying  the  camera  into  the  field.  The  methods  described  make  it  possible 
to  do  in  some  measure  for  aquatic  animals  what  has  been  done  for  birds  and  other 
terrestrial  forms. 

PRINCIPLES  OF  PHOTOGRAPHY  OF  SUBMERGED  OBJECTS. 

In  air  the  naturalist  can  by  one  method  or  another  photograph  what  he  sees. 
When  he  looks  into  clear  water  he  may  see  much  that  it  seems  possible  to  photo- 
graph. If  the  surface  is  disturbed  objects  beneath  it  appear  distorted  and  waver- 
ing, but  if  the  surface  is  smooth  they  may  appear  as  sharp  and  steady  as  though 

43 


44 


BULLETIN    OF    THE    BUREAU    OF    FISHERIES. 


viewed  through  air  alone.  In  the  latter  case  the  photographer  may  set  up  his 
camera  and  find  that  he  can  get  a  perfect  image  on  the  ground  glass;  but  if  he 
then  exposes  a  plate  with  the  expectation  of  getting  a  good  negative  he  will  be 
sorely  disappointed.  Only  rarely  does  he  get  any  image  at  all  of  what  lies  beneath 
the  water's  surface.  Usually  the  negative  shows  only  the  surface  itself,  and  that 
appears  as  opaque  as  though  the  camera  had  been  pointed  into  a  lake  of  tar.  The 
writer  has  often  attempted  such  photographs,  to  find  on  his  negative  no  visible 
impression  of  the  fish  which  showed  so  clear  on  his  ground  glass.  This  is  doubtless 
a  common  experience.  Why  is  it? 

Explanation  will  be  clearer  by  referring  to  the  diagrammatic  figure  1,  where 
the  camera   (c)  is  pointed  toward  a  fish   (x-y)   beneath  the  surface   (a-b)  of  the 

water.     The  fish 

^^  is       illuminated 

chiefly  by  rays  of 
light  which  enter 
the  water  almost 
vertically.  The 
rays  of  light  x  x', 
y  y',  reflected 
from  the  fish, 
which  strike  the 
surface  of  the 
water  from  below 
at  an  angle  less 
than  48°  35' with 
the  vertical, 
emerge  into  the 
air,  while  at  the 
same  time  they 
are  bent  from 
their  course,  as 
shown  in  the  fig- 
ure. Some  of 

these  rays  converge  to  the  lens,  and  thence  diverge  to  form  on  the  ground  glass 
the  image  i  i'.  When  the  photographic  plate  is  exposed  these  rays,  with  the  rays 
from  other  submerged  objects,  form  an  image  on  it,  as  they  do  on  the  ground 
glass.  Yet  this  image  does  not  appear  in  the  negative,  for  if  the  surface  of  the 
water  is  smooth  it  acts  as  a  single  great  mirror  which,  although  it  permits  a 
part  of  the  light  to  penetrate,  yet  reflects  another  part,  greater  the  more  obliquely 
the  light  strikes  the  surface.  For  this  reason  the  images  of  sky  and  trees 
and  other  distant  objects  are  often  seen  mirrored  on  the  surface  of  smooth  water. 
Some  of  these  reflected  rays  (z  z',  w  w'),  after  leaving  the  surface  of  the  water, 
enter  the  lens  of  the  camera  and  form  an  image.  The  fish  is  a  near  object  and  if 
the  camera  is  focused  upon  it  the  image  of  the  fish  is  sharp  on  the  photographic 
plate.  The  reflected  rays  from  the  water's  surface  come  usually  from  distant  objects, 
commonly  sky  or  clouds.  When  the  camera  is  focused  on  the  fish  a  sharp  image 


FIG.  1.— Diagram  illustrating  the  photography  of  objects  beneath  the  water  by  a  camera  above 
the  surface.    For  explanation  see  the  text. 


PHOTOGRAPHY    OF   AQUATIC    ANIMALS.  45 

of  these  distant  objects  is  formed,  not  on  the  photographic  plate,  but  in  a  plane 
situated  somewhere  between  that  plate  and  the  lens,  as  at  /  I' .  After  forming 
the  image  at  /  /'  these  rays  again  diverge  and  strike  the  photographic  plate.  The 
plate  is  thus  flooded  by  light  from  distant  objects  that  are  wholly  out  of  focus,  so 
that  such  rays  do  not  form  a  distinct  image  on  it.  This  reflected  light  is  usually 
brighter  than  the  light  which  forms  the  image  of  the  fish.  It  affects  the  plate 
with  greater  intensity,  so  that  when  the  plate  is  developed  the  image  of  the  fish  is 
quite  obscured  by  the  general  fog  produced  by  the  brighter  light.  There  appears 
in  the  negative  only  a  uniform  dark  haze,  which  represents  the  surface  of  the  water. 

If  the  ground  glass  is  put  in  place  and  brought  b\T  focusing  into  the  plane  /  /', 
then  the  sharp  image  of  distant  clouds  and  trees  is  seen  on  it,  while  the  image  of 
the  fish  lies  behind  the  ground  glass  and  is  no  longer  clearly  visible.  If  the  water 
is  smooth,  a  plate  exposed  under  these  circumstances  gives  a  sharp  negative  of 
these  distant  objects,  but  does  not  show  the  fish. 

If  one  looks  at  the  fish  in  the  water  from  the  point  C  it  is  seen  clearly,  because 
its  image  is  focused  on  the  retina,  while  the  images  of  more  distant  objects  mirrored 
in  the  water's  surface  fall  in  front  of  the  retina,  and  the  objects  from  which  they 
come  are  therefore  not  seen.  The  observer  neglects  the  glare  of  light  from  these 
distant  objects,  fixes  his  attention  on  the  fish,  and  sees  it.  If  now,  while  still 
looking  toward  the  fish,  he  adjusts  his  eye  to  distant  objects  by  relaxing  the  ciliary 
muscle,  these  are  clearly  seen  mirrored  in  the  surface  of  the  water,  while  the  fish  is 
no  longer  sharply  seen.  Similarly,  if  a  mirror  is  laid  on  the  ground  so  as  to  reflect 
the  clouds  and  its  image  is  examined  by  focusing  in  a  camera,  it  is  impossible  to 
get  at  the  same  time  on  the  ground  glass  a  sharp  image  of  the  clouds  reflected  in 
the  mirror  and  of  the  frame  of  the  mirror  or  other  near  object.  It  is  only  when 
the  mirrored  object  lies  near  the  surface  of  the  water  that  its  image  can  be  focused 
on  the  photographic  plate  or  retina  at  the  same  time  with  that  of  a  submerged 
object  near  the  surface.  It  nearly  always  happens  that  the  light  entering  the 
camera  from  distant  objects  mirrored  in  the  surface  of  the  water  is  so  much  more 
intense  than  that  from  submerged  objects  that  the  images  of  the  latter  are  quite 
obliterated  on  the  photographic  plate.  Sometimes,  on  the  other  hand,  when  the 
camera  is  pointed  nearly  vertically  into  the  water  at  an  object  over  a  light-colored 
bottom,  the  emerging  light  is  more  intense  than  the  reflected  light,  and  there  is 
obtained  a  more  or  less  fogged  negative  which  shows  submerged  objects.  This  is 
the  more  apt  to  be  the  case  if  the  photographer  has  the  sun  at  his  back.  (See 
Saville-Kent,  1893.)  At  other  times,  within  the  limits  of  the  reflected  image  (not 
the  shadow)  of  a  dark-colored  bridge  or  building  or  of  dense  foliage,  one  may  obtain 
a  fogged  negative,  showing  submerged  objects.  In  this  case  also  the  partial  success 
is  due  to  the  fact  that  the  reflected  light  is  less  intense  than  that  which  comes  from 
the  submerged  objects  to  be  photographed.  It  is  not  often,  however,  that  the 
submerged  objects  that  one  wishes  to  photograph  are  found  within  the  reflected 
images  of  dark-colored  backgrounds  of  sufficient  size  and  far  enough  away. 

The  above  discussion  is  based  on  the  assumption  that  the  surface  of  the  water 
is  smooth  so  that  it  acts  as  a  single  large  mirror.  If  the  water  surface  is  disturbed 
it  is  broken  into  numerous  smaller  surfaces,  concave,  convex,  or  plane,  and  each 
of  these  acts  as  an  independent  small  mirror.  These  form  distorted  images  of 


46  BULLETIN    OF    THE    BUREAU    OF    FISHERIES. 

portions  of  distant  objects,  of  natural  size,  magnified  or  reduced;  and  the  light 
from  them  entering  the  camera  affects  the  photographic  plate  in  such  a  way  as 
to  obliterate  the  dimmer  image  of  any  object  lying  beneath  the  water.  At  the 
same  time  the  light  from  the  submerged  object  is  refracted  in  various  directions 
as  it  emerges  into  the  air  through  the  irregular  surface  of  the  water,  so  that  its 
image  as  formed  on  the  retina  or  ground  glass  is  neither  sharp  nor  steady. 

From  the  foregoing  discussion  it  appears  that  attempts  to  photograph  sub- 
merged objects  with  a  camera  placed  in  air  can  result  in  only  partial  success,  and 
this  but  rarely.  Failure  is  due  to  the  fact  that  the  photograph  is  made  through 
the  surface  of  contact  of  two  media,  water  and  air,  of  very  different  refractive 
powers.  If  this  surface  is  not  perfectly  smooth  the  light  from  an  object  beneath 
it  is,  upon  emergence,  refracted  unequally  at  different  parts  of  the  surface  and  can 
not  form  a  clear  image  on  the  ground  glass.  Whether  the  water  is  smooth  or  rough 
its  surface  reflects  a  part  of  the  light  which  strikes  it,  and  thus  acts  as  a  mirror. 
This  reflected  light  makes  it  impossible,  except  under  unusual  conditions,  to  obtain 
photographs  of  submerged  objects.  To  obtain  such  photographs  the  surface  of 
the  water  must  be  smooth  and  light  reflected  from  it  must  not  enter  the  camera. 
Two  modes  of  procedure  suggest  themselves: 

(1)  The  camera  may  remain  above  the  surface  of  the  water.     In  that  case  the 
surface  of  disturbed  water  must  be  rendered  smooth  and  the  light  from  objects 
above  water  must  be  prevented  from  striking  its  surface  at  such  angles  as  to  enter 
the  camera  in  sufficient  amount  to  fog  the  plate.     Methods  devised  by  the  writer 
for  accomplishing  these  two  results  are  taken  up  and  illustrated  in  the  following 
section. 

(2)  The  camera  may  he  placed   heneath  the  surface  of  the  water,  so  that  this 
surface  does  not  intervene  between  the  camera  and  the  object  to  be  photographed. 
The  light  which  enters  the  camera  is  therefore  neither  refracted  nor  reflected  at 
this  surface,  and  images  may  be  obtained  on  the  ground  glass  as  clear  and  steady 
as  though  viewed  through  air  alone.     Methods  of  the  writer  and  others  for  accom- 
plishing this  are  described  and  illustrated  in  the  final  section  of  this  paper. 

A  NEW  METHOD  OF  PHOTOGRAPHING  SUBMERGED  OBJECTS  WITH  THE  CAMERA 

ABOVE  THE  SURFACE. 

It  was  pointed  out  in  the  preceding  section  that  if  the  camera  with  which  sub- 
merged objects  are  to  be  photographed  is  to  remain  above  the  surface  of  the  water 
means  must  be  found  (1)  greatly  to  reduce  the  amount  of  reflected  light  entering 
the  camera  from  the  surface  of  the  water,  and  (2)  to  render  the  surface  of  the  water 
smooth.  We  may  consider  first  the  case  in  which  the  surface  of  the  water  is  smooth, 
so  that  it  is  necessary  merely  to  minimize  surface  reflection. 

The  method  to  be  described  is  best  adapted  to  objects  in  water  not  more 
than  2  or  3  feet  deep,  and  the  best  results  are  obtained  when  the  water  is  less 
than  a  foot  in  depth.  Any  type  of  camera  may  be  used,  but  since  the  objects  to 
be  photographed  are  necessarily  quite  near  the  camera  they  are  out  of  focus  with 
a  fixed-focus  camera,  so  that  the  best  results  are  obtained  when  the  camera  is  one 
that  can  be  focused.  Since  the  objects  to  be  photographed  are  usually  in  motion, 
and  since  the  surface  of  the  water  may  at  any  time  be  roughened  by  a  puff  of  wind, 


PHOTOGRAPHY    OF    AQUATIC    ANIMALS. 


47 


it  is  best  to  use  a  lens  suitable  for  instantaneous  exposure — a  lens  of  a  speed  not  less 
than  f  8.  The  operator  should  first  select  the  point  from  which  the  picture  is  to 
be  taken.  He  should,  of  course,  have  the  sun  at  his  back  or  to  one  side.  If  possible 
he  should  stand  on  the  bank  or  on  some  fixed  support  which  extends  above  the 
surface  of  the  water.  From  such  a  position  the  camera  is  at  a  greater  height  and 
may  usually  be  directed  at  the  surface  of  the  water  at  an  angle  of  about  45°  or 
less  from  a  vertical  extending  upward  from  this  surface.  Rays  of  light  from  sub- 
merged objects  striking  the  surface  of  the  water  from  below  at  an  angle  of  48°  35' 
from  a  vertical  drawn  downward  (or  at  a  less  angle),  emerge.  They  may  thus, 
after  refraction,  reach  the  camera  as  indicated  by  the  line  x  yf  i'  in  figure  1.  Rays 
which  strike  the  surface  of  the  water  from  below  at  an  angle  of  more  than  48°  35' 
with  the  vertical  are,  on  the 
other  hand,  reflected  at  the 
surface  so  that  they  do  not 
emerge  and  enter  the  camera 
but  pass  down  again  into  the 
water,  as  indicated  by  the 
line  x  m  n  in  figure  1 . 

If  the  operator  is  unable 
to  find  a  fixed  emergent  sup- 
port for  the  camera  he  may 
make  the  exposure  while 
standing  in  the  water.  The 
camera  may  then  be  held  in 
the  hand  or  may  be  supported 
on  a  tripod  which  rests  on 
the  bottom.  As  the  legs  of 
the  tripod  are  likely  to  sink 
into  the  bottom  they  should 
be  extended  to  their  full 
length.  Where  the  bottom 
is  firm  an  elevated  position 
may  be  obtained  for  the 
camera  by  using  a  tripod  with  legs  some  10  feet  long,  such  as  dealers  sell  for  use 
in  making  pictures  of  large  groups.  In  such  tripods  one  leg  forms  a  ladder  by 
which  the  camera  may  be  reached. 

The  tripod  top  should  consist  of  two  rectangular  wooden  pieces,  as  shown  in 
figure  2  and  in  section  in  figure  1.  To  the  lower  piece,  which  has  a  large  circular 
opening  at  its  center,  the  legs  are  attached.  The  camera  is  fastened  by  the  tripod 
screw  to  the  upper  piece  in  such  a  way  that  one  of  the  legs  projects  directly  backward 
instead  of  directly  forward,  as  is  usual.  The  two  pieces  are  hinged  together  at  one 
edge,  so  that  they  may  lie  parallel  to  one  another  or  may  be  separated  like  the  covers 
of  a  book  until  the  upper  piece  forms  an  angle  of  90°  with  the  lower.  A  rod  is 
pivoted  by  one  end  to  the  upper  piece  at  the  middle  of  its  free  edge,  so  that  it  swings 
freely  in  the  vertical  plane.  This  rod  passes  through  a  perforated  metal  block  piv- 
oted by  one  end  at  the  middle  of  the  free  edge  of  the  lower  piece  so  as  to  swing  freely 


FIG.  2. — Tripod  top  by  means  of  which  the  camera  may  be  inclined  at  any 
angle.    For  explanation  see  the  text. 


48  BULLETIN    OF    THE    BUKEAU    OF    FISHERIES. 

in  a  plane  vertical  to  that  piece.  When  the  two  pieces  are  separated  by  moving  the 
upper  one  on  the  hinge  which  connects  them  the  rod  slips  through  the  opening  in 
the  block  and  may  be  firmly  clamped  at  any  point  in  its  length  by  means  of  a 
set  screw.  Thus  the  upper  piece  may  be  held  firmly  at  any  angle  to  the  lower 
piece  from  0°  to  90°,  and  the  camera  may  be  pointed  at  the  water  at  any 
desired  angle.  The  position  in  which  the  legs  of  the  tripod  are  attached  permits  the 
camera  to  be  pointed  directly  downward  in  the  space  between  the  two  front  legs, 
whereas  if  the  legs  were  attached  in  the  usual  manner  with  one  leg  in  front  it  would 
be  impossible  to  bring  the  camera  into  the  vertical  position.  Tripods  of  this  type 
are  to  be  found  in  the  market  or  may  be  made  from  an  ordinary  tripod  by  any 
mechanic. 

When  the  operator  has  placed  his  camera  and  roughly  adjusted  it,  he  should 
set  up  a  screen  to  cut  off  the  light  reflected  from  the  surface  of  the  water  into  the 
camera.  Any  piece  of  dark  fabric,  a  blanket,  shawl,  or  for  small  objects  even  a 
coat,  may  be  used.  It  may  be  supported  by  hand  or  tied  to  poles  stuck  in  the 
bottom.  The  writer  carries  into  the  field  a  screen  made  by  sewing  together  pieces 
of  black  calico  to  form  a  sheet  either  6  or  9  feet  square.  To  three  of  the  edges 
of  this,  at  intervals  of  about  a  foot,  are  sewn  pieces  of  tape  each  about  a  foot  long  and 
attached  at  its  middle  so  as  to  leave  6  inches  projecting  on  each  side.  One  piece 
of  tape  should  be  attached  to  each  corner  of  the  screen.  Two  poles  are  cut  of 
sufficient  length  to  project  6  to  10  feet  above  the  wrater  when  firmly  set  in  the 
bottom.  The  poles  are  sharpened  at  one  end,  and  beginning  at  the  unsharpened 
end  the  square  of  calico  is  tied  to  them  by  the  opposite  edges  by  means  of  the 
tapes.  The  third  side  to  which  tapes  are  attached  is  the  upper,  between  the 
unsharpened  ends  of  the  poles.  The  poles  are  now  thrust  into  the  bottom  on  that 
side  of  the  camera  opposite  the  object  to  be  photographed  and  so  that  they  slant 
toward  the  camera.  The  screen  (s  s',  fig.  1)  is  thus  stretched  upward  from  the 
surface  of  the  water  in  a  slanting  position,  so  that  its  upper  edge  is  nearer  the  camera 
than  its  lower.  If  the  two  poles  are  pulled  together  by  the  weight  of  the  cloth  or  the 
action  of  the  wind  so  that  the  screen  sags,  a  third  pole  tied  between  their  upper 
ends  will  keep  them  apart,  while  the  tapes  on  the  upper  edge  of  the  screen  will 
serve  to  attach  it  to  the  cross-pole. 

If  the  operator  now  returns  to  the  camera  he  will  see  the  screen  mirrored  in 
the  surface  of  the  water.  The  object  to  be  photographed  should  fall  within  the 
limits  of  this  mirrored  image  as  seen  from  the  camera.a  If  it  does  not,  the  screen 
or  the  camera  must  be  shifted  until  it  does.  The  operator  will  see  also  the  shadow 
of  the  screen.  This  should  not  fall  on  the  object  to  be  photographed.  The  screen 
should,  if  possible,  be  adjusted  by  slanting  it  or  by  moving  one  of  the  poles  so  that 
the  sun  strikes  it  nearly  edgewise,  but  yet  does  not  strike  that  face  of  it  which  is 
toward  the  camera.  If  this  adjustment  is  properly  made  the  shadow  of  the  screen 
is  a  very  narrow  band,  which  lies  beneath  the  screen  and  a  little  nearer  the  camera 
than  its  lower  edge.  The  full  sunlight  then  falls  on  the  object  while  the  rays  from 

a  Saville-Kent  (1893)  apparently  utilized  this  principle  when  photographing  with  a  vertical  camera  on  the  Australian 
barrier  reefs,  but  Rudaux  (1908)  stated  the  principle  explicitly  as  applied  in  photographing  in  natural  waters  with  a 
vertical  camera  objects  within  the  reflected  image  of  the  tripod  top.  Neither  recognized  the  broad  application  of  the 
principle  here  described. 


PHOTOGRAPHY    OF    AQUATIC    ANIMALS.  49 

distant  objects  which  would  otherwise  be  reflected  into  the  camera  from  the  surface 
of  the  water  are  cut  off.  If  the  sunlight  is  permitted  to  fall  on  that  face  of  the 
screen  which  is  toward  the  camera,  it  is  reflected  from  the  screen  to  the  surface  of 
the  water  and  thence  into  the  camera.  A  picture  taken  under  these  conditions 
may  show,  besides  the  object  under  the  water,  also  the  screen  itself,  although  this 
image  of  the  screen  is  usually  so  faint  that  it  does  not  interfere  with  the  use  of  the 
picture  for  scientific  purposes. 

When  the  screen  has  been  properly  set  the  operator  has  merely  to  adjust  the 
camera  and  make  the  exposure  in  the  customary  way.  If  the  subjects  are  fish  they 
will  usually  have  been  frightened  away,  but  if  the  fish  are  engaged  in  nest  building 
or  in  some  other  occupation  that  attracts  them  to  a  particular  spot,  they  will,  in 
most  cases,  return  after  a  tune  varying  from  five  minutes  to  an  hour.  The  operator 
has  merely  to  remain  quiet  until  this  happens.  The  photographer  may  focus  his 
camera  on  the  spot  to  which  the  fish  is  likely  to  return  and  then  withdraw  and 
operate  the  camera  from  a  distance  by  pulling  a  string  or  pressing  a  bulb  when 
the  fish  returns.  The  method  is  of  most  use  in  securing  photographs  of  the  nests 
and  habitats  of  fish  in  shallow  water,  yet  the  writer  has  succeeded  by  means  of  it 
in  making  some  satisfactory  photographs  of  fish  on  the  nest. 

The  result  of  using  the  screen  is  shown  in  figure  1  of  plate  ni,  which  is  a  photo- 
graph of  the  nest  of  a  small-mouthed  black  bass.  The  screen  in  this  case  was  stretched 
on  a  frame  and  was  held  by  hand.  Within  the  limits  of  the  reflection  of  the  screen 
in  the  water's  surface  the  bottom  may  be  seen  clearly.  At  the  center  are  the  larger 
stones  which  form  the  bottom  of  the  nest,  and  these  show  sharply  the  details  of 
then"  markings.  Outside  the  limits  of  the  reflection  of  the  screen  the  bottom  is  not 
clearly  visible;  its  image  has  been  obscured  on  the  sensitir'e  plate  by  the  bright 
light  reflected  from  the  surface  of  the  water.  The  sun  struck  the  back  of  the  screen 
from  the  left,  as  is  shown  by  the  shadow  which  lies  close  to  the  screen.  Within 
the  limits  of  this  shadow  the  plate  was  underexposed  and  details  of  the  bottom 
are  not  visible.  With  a  longer  exposure  as  good  a  negative  could  have  been  made 
of  what  lay  in  the  shadow. 

If  the  surface  of  the  water  is  not  smooth  it  may  be  made  so  by  a  water  glass, 
which  may  be  constructed  as  follows  (fig.  1,  pi.  iv):  A  square  frame  is  made  of 
heavy  galvanized  iron,  and  measures  3$  inches  deep  and  12  inches  on  each  side 
within.  One  of  its  edges  (the  top)  is  turned  outward  three-fourths  of  an  inch  and 
then  downward  one-half  inch  to  form  a  lip.  This  stiffens  the  frame  and  tends  to  pre- 
vent water  from  slopping  into  it.  The  lower  edge  of  the  frame  is  turned  outward 
about  half  an  inch  to  form  a  flat  surface,  against  which  the  glass,  13  inches  square,  is 
bedded  in  aquarium  cement.  After  the  glass  is  in  position  four  trough-shaped  pieces 
are  soldered  to  the  sides  of  the  frame  and  to  one  another  in  the  manner  shown  in  the 
figure.  The  free  edges  of  these  pieces  project  inward  beneath  the  lower  surface  of 
the  glass  and  support  it.  Before  the  pieces  are  soldered  into  place  cement  is  placed 
between  them  and  the  lower  face  of  the  glass.  The  whole  border  of  the  glass  is  thus 
bedded  in  cement  on  both  surfaces  and  at  the  edge.  To  protect  the  glass  when  not  in 
use  a  flat  cover  is  provided,  which  fits  against  its  lower  face.  Such  a  water  glass  may 

B.  B.  F.  1907—4 


GO  BULLETIN    OF    THE    BUREAU    OF    FISHERIES. 

be  floated  over  the  object  to  be  photographed  and  a  screen  set  up  independently 
of  it,  or  the  screen  may  be  attached  to  the  glass  itself.  For  the  latter  purpose  a 
piece  of  half -inch  band  iron  may  be  bent  to  form  the  three  sides  of  a  rectangle, 
8  by  12  inches,  and  this  may  be  riveted  as  a  bail  (fig.  1,  pi.  iv)  to  the  inside  of  the 
frame,  about  8  inches  from  one  side.  The  bail  should  turn  on  the  rivets  so  that  it 
may  be  depressed  into  the  frame  when  not  hi  use.  A  screen  may  be  formed  by 
raising  the  bail  and  tying  a  piece  of  black  cloth  from  it  to  the  opposite  side  of  the 
frame.  In  shallow,  running  water  it  is  desirable  to  support  the  water  glass  from 
the  bottom  in  order  that  it  may  not  sink  so  much  as  to  displace  or  distort  the 
object  to  be  photographed.  It  may  be  supported  on  four  iron  rods  which  run 
through  metal  sleeves  soldered  to  the  four  corners  of  the  frame.  The  rods  may 
be  fixed  in  any  position  in  the  sleeves  by  means  of  set  screws,  and  may  project 
upward  far  enough  to  support  the  upper  edge  of  the  screen.  A  water  glass 
arranged  in  this  way  is  shown  in  figure  2,  plate  iv,  where  it  is  being  used  for  observa- 
tion, but  with  the  same  glass  photographs  were  obtained  of  lamprey  eels  in  the  act  of 
spawning.  Such  a  photograph  is  reproduced  in  figure  2,  plate  HI,  where  the  rough 
surface  of  the  running  water  made  the  use  of  the  water  glass  imperative.  The 
white  bands  across  the  picture  are  the  edges  of  the  frame  of  the  water  glass.  Outside 
this  frame  at  the  right,  where  the  water  is  rough,  little  is  visible.  The  screen  was 
almost  as  necessary  as  the  water  glass. 

The  writer  has  used  water  glasses  of  this  type  varying  in  size  from  1  to  3  feet 
square.  Those  of  1  foot  square  are  of  use  chiefly  for  observation,  and  even  for 
this  purpose  the  screen  is  a  valuable  addition.  Those  of  3  feet  square  are  so 
unwieldy  that  a  vehicle  of  some  sort  is  needed  to  carry  them.  The  size  most  suitable 
for  field  photography  is  2  feet  square,  since  this  may  be  transported  by  hand. 

The  method  described  in  this  section  is  suited  only  to  shallow  water,  where 
the  camera  may  be  supported  from  a  firm  substratum.  In  deeper  water  the 
unsteadiness  of  the  boat  would  interfere  with  the  manipulation  of  a  water  glass  or 
a  screen.  It  might  be  possible,  however,  to  construct  a  boat  of  which  the  water 
glass  and  the  screen  should  form  constituent  parts.  The  method  described  permits 
only  of  views  at  angles  of  from  about  48°  to  90°  to  the  water's  surface.  Since  it  is 
not  practicable  to  place  the  camera  far  above  the  water  at  these  angles  or  to  use 
screens  of  very  large  size,  the  pictures  that  may  be  taken  are  of  near  objects  and 
the  field  covered  by  them  is  of  limited  extent.  If  a  water  glass  is  used,  the  camera 
must  be  near  it  and  the  field  is  limited  by  its  frame.  The  method  is,  however,  the 
only  one  known  to  the  writer  for  certain  kinds  of  work.  Often,  as  in  the  case  of 
the  bass  nest  shown  in  figure  3,  the  objects  to  be  photographed  are  in  water  so 
shallow  that  the  camera  must  be  placed  above  its  surface;  there  is  not  room  for  it 
beneath.  Often,  though  the  object  may  be  in  deeper  water,  it  is  so  surrounded 
by  vegetation  that  it  can  not  be  seen  from  a  little  distance  except  from  above.  It 
must  then  be  photographed  from  above.  Where  the  water  is  both  shallow  and 
disturbed,  as  in  small  streams,  the  use  of  a  water  glass  is  essential.  There  are  there- 
fore many  objects  about  the  borders  of  lakes  and  in  streams  to  which  this  method 
may  be  applied  when  no  other  known  method  is  available.  On  the  other  hand, 
wherever  it  is  possible  to  use  a  submerged  camera,  results  may  be  obtained  with 
greater  ease  and  certainty  in  the  mariner  shown  in  the  section  which  follows. 


PHOTOGRAPHY    OF    AQUATIC    ANIMALS.  51 

PREVIOUS  ATTEMPTS  TO  PHOTOGRAPH  SUBMERGED  OBJECTS  BY  MEANS  OF  A 

SUBMERGED  CAMERA. 

Photography  by  means  of  a  submerged  camera  was  first  attempted  by  Dr.  L. 
Boutan,  of  Paris,  at  the  seaside  laboratory  of  Roscoff,  in  1893.  His  work  was  con- 
tinued through  the  seasons  of  1895,  1896,  1897,  and  1898,  and  the  results  have  been 
published  in  four  communications  (Boutan,  1893,  1898,  1898a,  1900).  Boutan's 
apparatus  was  used  wholly  in  the  sea,  and  he  has  given  to  his  method  the  title  "la 
photographic  sous-marine."  I  shall  use  instead  the  broader  term  subaquatic 
photography,  as  indicating  the  wider  application  of  the  method  to  both  fresh  and 
salt  water. 

Boutan  made  use  of  three  forms  of  apparatus,  which  may  be  designated  as  his 
first  (1893),  second  (1896),  and  third  (1898)  apparatus.  Each  of  these  will  be 
briefly  considered. 

He  was  led  to  take  up  subaquatic  photography  by  his  study  of  the  develop- 
ment of  the  mollusk  Haliotis.  Finding  it  impossible  to  rear  the  larva?  of  this  form 
in  aquaria  and  failing  to  collect  them  in  their  natural  environment  by  the  usual 
methods,  he  decided  to  search  for  them  by  descending  in  a  diver's  suit.  He  was 
struck  by  the  beauty  and  interest  of  the  submarine  landscape  and  of  its  inhabit- 
ants. He  found  it  impossible  to  bring  his  experiences  vividly  before  others  by 
mere  verbal  description  and  equally  impossible,  while  inclosed  in  the  cumbersome 
garments  of  the  diver,  to  make  drawings,  or  even  sketches,  of  what  he  saw.  He 
was  thus  led  to  try  photography.  He  appears  to  have  made  no  attempt  to  oper- 
ate with  a  camera  placed  above  the  water,  for,  as  he  says,  "when  the  surface  of  the 
liquid  is  absolutely  quiet  the  rays  of  light  coming  from  submerged  objects  enter  the 
objective  placed  in  air  at  the  same  time  with  the  rays  reflected  by  this  mirroring 
surface  and  that  suffices  to  destroy  all  clearness  in  the  images."  He  objected  to 
this  method  for  the  further  reason  that  it  could  result  in  giving  only  a  plan  or 
bird's-eye  view  similar  to  that  which  is  obtained  when  landscapes  are  photographed 
from  the  elevated  car  of  a  balloon.  He  therefore  decided  to  construct  an  appara- 
tus that  could  be  used  under  water.  It  seemed  to  him  possible  to  proceed  on  either 
one  of  two  principles:  (1)  "To  have  made  an  objective  that  could  be  immersed 
directly  in  water.''  (2)  "To  have  built  a  tight  box  in  the  interior  of  which  the 
ordinary  objective  could  be  placed  protected  from  salt  water."  In  his  first  and 
third  forms  of  apparatus  Boutan  made  use  of  the  second  principle.  In  his  second 
attempt  he  made  use,  without  success,  of  an  objective  immersed  in  water. 

BOUT  AX'S    FIRST    APPARATUS    (1893). 

In  this  apparatus  Boutan  made  use  of  a  detective  camera  of  fixed  focus,  an 
instrument  intended  to  make  instantaneous  pictures  at  all  distances  beyond  3  or  4 
meters  without  focusing.  This  camera  was  of  the  box  form  usual  in  detective 
cameras.  It  was  provided  at  the  front  with  an  opening  for  the  lens  and  above 
this  with  two  openings  for  the  finder.  At  the  front  there  was  on  one  side  a  lever 
or  button  which  controlled  the  shutter  and  at  the  back  a  rod  by  the  movement  of 
which  it  was  possible,  without  opening  the  box,  to  change  the  plates,  a  number  of 
which  were  carried  in  the  magazine  of  the  camera. 


52 


BULLETIN    OF    THE    BUREAU    OF    FISHERIES. 


OB 


This  camera  was  inclosed  in  a  copper  box  (fig.  3).  The  top  of  the  box  was 
open  and  was  stiffened  by  a  projecting  rim  against  which  a  cover  could  be  clamped 
by  means  of  eight  metal  screw-clamps.  The  joint  between  the  rim  of  the  box  and 
the  cover  was  made  water-tight  by  means  of  a  heavy  rubber  gasket  let  into  rectan- 
gular grooves  in  both  the  rim  and  the  cover.  The  box  was  intended  to  be  used 
at  considerable  depths.  The  pressure  of  the  water  on  its  outside  would  at  10 
meters  depth  be  one  atmosphere  plus  the  pressure  exerted  by  a  column  of  water  10 
meters  high,  while  the  pressure  on  the  inside  of  the  box  would  be  what  it  was  when 
the  box  was  closed  at  the  surface,  one  atmosphere.  Under  these  circumstances 
there  was  serious  danger  that  the  excess  pressure  on  the  outside  of  the  box  would 
force  the  water  through  between  the  rim  and  the  cover  in  spite  of  the  most  care- 
ful construction  of  the  joint  between  the 
two.  To  overcome  this  difficulty,  the  cover 
of  the  box  was  provided  at  its  center  with 
an  opening  which  extended  upward  into  a 
metal  tube,  and  to  this  tube  there  was  at- 
tached an  air-filled  rubber  bag  of  about 
3  liters  capacity.  When  the  box  was  sub- 
merged the  pressure  of  the  water  on  the 
bag  was  communicated  to  the  air  within, 
so  that  the  pressure  on  the  inner  surface 
of  the  box  was  exactly  equal  at  all  depths 
to  that  on  its  outer  surface.  Thus  there 
was  no  excess  pressure  on  the  outer  surface 
of  the  box  to  force  the  water  inward  against 
a  less  pressure  within. 

The  front  of  the  box  was  provided  with 
three  circular  openings  closed  by  plates 
of  glass  with  parallel  surfaces.  The  one  at 
the  center  was  opposite  the  lens;  the  two 
above  it  were  for  the  finder.  A  similar 
opening  on  one  side  was  also  closed  by 
a  glass  plate  and  served  for  the  finder.  On  the  same  side  was  a  rod  which 
terminated  at  its  outer  end  in  a  milled  head.  Its  inner  end  extended,  through  a 
stuffing  box  which  was  water-tight,  to  the  interior  of  the  box.  By  pulling  the 
rod  in  and  out  the  shutter  could  be  operated.  A  similar  rod  at  the  back  of  the  box 
could  be  slid  in  and  out  and  served  to  change  the  plates.  When  in  use  the  camera 
was  supported  on  a  heavy  tripod  of  iron. 

The  apparatus  was  used  either  while  the  operator  remained  in  shallow  water 
with  his  head  and  shoulders  above  the  surface  or  when  he  had  descended  to  the 
bottom  in  a  diver's  suit.  When  working  in  shallow  water,  he  put  on  the  diver's 
suit  in  order  to  be  protected  from  the  water,  but  omitted  the  casque  covering  the 
head  and  the  heavy  weight  ordinarily  attached  to  the  back  and  front  of  the  suit. 
Thus  arrayed,  he  placed  the  tripod  in  position  and  attached  the  camera  to  it.  In 


FIG.  3.— Boutan's  first  apparatus.  Box  used  in  1893  for 
inclosing  a  detective  camera  to  be  used  under  water. 
B,  rubber  balloon  filled  with  air;  D,  handle  at  the 
back  for  operating  the  magazine  plate  holder;  O,  open- 
ing corresponding  to  the  lens;  OB,  handle  at  the  side 
controlling  the  shutter;  V,  front  finder;  OV,  lateral 
finder.  (Copy  of  fig.  1  in  Boutan,  1893.) 


PHOTOGRAPHY    OF    AQUATIC    ANIMALS.  53 

order  to  bring  the  camera  to  bear  on  the  object  to  be  photographed,  it  was  then 
necessary  to  provide  a  way  to  determine  when  the  image  of  the  object  appeared  in 
the  desired  position  in  the  finder.  This  was  accomplished  by  using  a  metal  tube  open 
at  both  ends,  one  end  of  the  tube  being  placed  over  the  ground  glass  of  the  finder 
and  the  other,  which  extended  above  the  water,  being  applied  to  the  eye.  The  tube 
excluded  the  light  from  the  space  between  the  eye  of  the  observer  and  the  finder, 
while  at  the  same  time  the  water  within  it  was  protected  from  agitation.  By  this 
means  it  was  possible  to  see  clearly  the  image  on  the  ground  glass  of  the  finder. 
It  was  necessary  merely  to  manipulate  the  handle  controlling  the  shutter  in  order 
to  begin  and  end  the  exposure.  The  plate  could  then  be  changed  by  manipulat- 
ing the  rod  at  the  back  of  the  box  and  another  exposure  made  at  once  without 
taking  the  camera  from  thex  water.  Where  it  was  possible  to  operate  near  shore, 
it  was  unnecessary  for  the  operator  to  put  on  the  diver's  suit  or  to  enter  the  water. 
He  could  set  the  camera  in  place  from  the  shore  and  adjust  it  or  make  the  exposure 
while  lying  upon  the  bank.  Boutan,  indeed,  made  satisfactory  photographs  of 
fixed  animals  in  aquaria  by  immersing  this  apparatus  in  an  indoor  aquarium  and 
operating  it  by  means  of  a  string.  By  using  a  very  small  diaphragm  he  was  able 
to  get  clear  images  of  objects  at  a  distance  of  15  centimeters  from  the  lens,  but 
this  required  an  exposure  of  three  minutes.  He  obtained  photographs  of  fish  and 
other  mobile  forms  in  the  same  manner  by  inclosing  the  animal  to  be  photographed 
in  a  glass  globe,  which  was  then  immersed  in  the  aquarium  at  a  suitable  distance 
from  the  lens.  The  globe  served  to  restrict  the  movements  of  the  animal.  When 
working  in  shallow  water,  he  found  that  the  algae  which  appear  everywhere  in  the 
submarine  landscape  were  in  constant  motion  whenever  there  was  any  movement 
of  the  water.  It  was  therefore  necessary  to  restrict  operations  to  those  days  on 
which  it  was  perfectly  calm. 

In  order  to  obtain  photographs  at  depths  at  which  it  was  impossible  to  wade 
Boutan  made  use  of  the  diver's  outfit.  He  describes  the  outfit  in  detail  and  the 
method  of  using  it  in  a  very  interesting  section  of  his  paper  of  1898.  The  method  of 
procedure  was  briefly  as  follows:  The  boat  containing  the  apparatus  to  be  used 
(diver's  suit,  air  pumps,  and  photographic  apparatus)  was  first  firmly  anchored  at  the 
spot  selected  and  held  in  place  by  means  of  cables  stretched  to  the  rocks  on  shore. 
The  photographer  then  put  on  the  diver's  suit  and  descended  to  the  point  selected  as 
the  center  of  operations.  He  first  signaled  to  an  assistant  to  let  down  the  photo- 
graphic apparatus,  which  consisted  of  the  tripod,  the  box  containing  the  camera,  and 
a  weight  intended  to  steady  the  apparatus.  He  then  sought  out  the  view  to  be 
taken  and  set  up  the  apparatus  at  his  leisure.  This  accomplished,  he  opened  the 
shutter  of  the  camera  and  signaled  to  the  assistant  that  the  exposure  was  begun. 
Since  it  was  impossible  to  use  a  watch  while  under  water  it  was  necessary  that  the 
assistant  in  the  boat  above  should  time  the  exposure.  At  the  expiration  of  the 
time  agreed  upon  the  assistant  signaled  and  the  photographer  closed  the  shutter. 
When  the  weather  was  good  and  the  sun  shining  an  exposure  of  ten  minutes  was 
necessary  with  a  small  diaphragm  at  a  depth  of  5  meters.  Boutan  estimated 
that  at  a  depth  of  10  meters  this  exposure  would  need  to  be  more  than  doubled. 


54 


BULLETIN    OF    THE    BUREAU    OF    FISHERIES. 


-V 


BOUTAX'S    SECOND    APPARATUS    (1896). 

This  apparatus  (fig.  4)  consisted  of  a  metal  camera,  not  inclosed  in  a  box, 
but  intended  to  be  immersed  directly  in  sea  water.  The  sea  water  could  enter 
and  fill  the  interior  of  the  camera  so  that  it  bathed  both  the  front  and  back  faces  of 
the  lens  as  well  as  the  plates.  The  latter  were  contained  in  a  holder  which  could 
be  attached  to  the  camera  after  it  was  submerged.  Thus  the  plates  could  be 
changed  under  water  without  any  risk  of  fogging  them.  Sea  water  was  found  to 
have  little  effect  on  the  plates  unless  its  action  was  prolonged,  and  this  effect  could 
be  wholly  prevented  by  using  plates  that  had  been  varnished. 

The  lens  used  with  this  apparatus 
was  one  intended  for  use  in  air,  and  it 
was  found  that  good  results  could  not 
be  obtained  with  it  when  immersed  in 
water.  The  success  of  such  an  appa- 
ratus as  this  must  depend  on  having  a 
lens  especially  ground  for  use  under 
water.  No  lens  of  this  sort  existed  and 
to  have  one  calculated  and  made  would 
have  been  expensive.  For  this  reason 
and  for  others  which  he  mentions 
Boutan  abandoned  this  apparatus  after 
trying  it  for  a  single  season.  He  says, 
"The  principle  is  certainly  good,  and, 
in  spite  of  the  failure  that  I  have  made 
in  the  application  of  it,  the  future  of 
submarine  photographic  apparatus  may 
lie  there." 

BOUTAN'S  THIRD  APPARATUS  (1898). 

As  a  result  of  the  failure  of  his 
second,  Boutan  adopted  a  third  appa- 
ratus, which  was  in  principle  a  return 
to  the  first.  This  third  apparatus, 
designed  for  instantaneous  work,  consisted  of  a  heavy  metal  box,  shown  at  the  center 
in  figure  5.  To  it  are  attached  four  adjustable  legs.  The  box,  which  is  watertight, 
contains  the  objective  and  the  plates.  It  is  itself  the  camera  and  does  not  therefore 
contain  within  it  a  camera,  to  be  lifted  out  and  put  back.  The  lens  is  a  Darlot 
symmetrical-anastigmatic  of  excellent  quality.  At  the  front  is  an  opening  (O) 
closed  by  a  plate  of  glass,  through  which  the  light  enters  the  lens.  There  are  no 
finders  and  consequently  no  openings  closed  by  glass  plates,  with  the  exception 
of  that  for  the  lens.  At  the  top,  in  front,  is  a  handle  by  means  of  which  the  shutter 
may  be  operated.  About  the  center  of  the  box  is  clamped  a  band-iron  frame  with 
a  ring  at  the  top  by  means  of  which  the  box  may  be  attached  to  a  rope  for  lifting 
it  in  and  out  of  the  boat.  At  the  back  is  a  cover  which  may  be  fastened  by  means 


FIG.  4. — Boutan's  second  apparatus.  B,  camera  box  into 
which  the  water  could  penetrate  freely;  m,  handle  control- 
ling the  plate  holder;  m',  handle  controlling  the  shutter; 
O,  objective;  V,  sight.  (Copy  of  fig.  2  in  Boutan,  1898.) 


PHOTOGRAPHY    OF    AQUATIC    ANIMALS. 


55 


of  screws  against  a  rubber  packing  on  the  end  of  the  box,  so  that  the  joint  between 
cover  and  box  is  made  water  tight.  The  rubber  bag  used  in  the  first  apparatus 
seems  to  have  been  found  unnecessary  and  is  at  any  rate  omitted.  At  the  back 
of  the  cover  there  projects  a  handle  (M)  by  the  manipulation  of  which  the  plates 
may  be  changed.  On  the  top  at  V  is  a  sight  by  means  of  which  the  camera  may 
be  directed  at  the  desired  object.  Within  the  box  at  the  back  is  a  magazine  plate 
holder  for  six  plates.  This  is  represented  at  the  left  at  C  H  in  figure  9.  It  is  so 
arranged  that  when  a  plate  has  been  exposed  it  may  be  made  to  fall  forward  by 
turning  the  handle  shown  at  M  in  the  central  figure.  A  second  plate  is  at  the 
same  time  pushed  into  place  by  springs.  When  this  has  been  exposed  a  second 
turn  of  the  handle  allows  the  plate  to  fall  and  a  third  plate  comes  into  place.  Six 
plates  may  thus  be  exposed  without  opening  the  box.  On  each  side  of  the  plate 
holder  are  two  cleats  (gl) .  These  glide  upon  two  rails  on  the  inside  of  the  box,  one 
on  either  side,  so  that 
the  plate  holder  may  be 
moved  back  and  forth 
on  the  rails  away  from 
the  lens  or  toward  it. 
By  means  of  a  set  screw 
the  plate  holder  may  be 
firmly  clamped  at  any 
point  on  the  rail.  The 
camera  is  focused  by 
means  of  this  movement 
of  the  plate  holder.  To 
prevent  reflection  of 
light  from  the  lower 
side  of  the  surface  film 
of  the  water  into  the 
camera  there  is  pro- 
vided a  semicylindrical 
shade  shown  at  A  B  on  the  right  in  figure  5.  It  may  be  attached  to  the  front  of 
the  box  above  the  lens  by  the  arrangement  shown  at  X. 

It  is  not  possible  to  focus  after  the  box  has  been  closed  in  order  to  immerse  it. 
Consequently  one  of  the  rails  upon  which  the  plate  holder  moves  must  be  provided 
with  a  scale.  The  divisions  on  this  scale  correspond  to  different  distances  between 
the  lens  and  the  object  to  be  photographed.  When  the  plate  holder  is  set  at  a 
certain  division  of  the  scale  the  camera  is  in  focus  for  objects  at  a  distance  of  4 
meters;  when  set  at  another  division  for  objects  at  2  meters.  It  is  therefore 
necessary  to  determine  before  the  camera  box  is  closed  at  what  distance  the  object 
is  to  be  photographed  and  to  focus  by  setting  the  plate  holder  at  the  corresponding 
division  on  the  scale.  While  the  box  is  immersed  this  focus  cannot  be  changed. 
The  divisions  to  be  marked  on  this  scale  were  ob  tamed  by  focusing  on  submerged 
objects  while  the  front  of  the  camera  was  also  submerged.  This  necessitated  the 
use  of  special  devices,  which  need  not  be  described  here. 


FIG.  5. — Boutan's  third  apparatus  (1893).  A,  metal  camera  box;  M,  handle  control- 
ling the  changing  of  plates;  MO,  handle  controlling  the  shutter;  O,  opening  for 
the  lens;  P,  feet  for  supporting  the  apparatus;  V,  sight;  X,  points  of  attachment 
of  the  hood  AB;  CII,  magazine  holder  for  six  plates;  gl,  cleats  by  means  of 
which  the  holder  glides  on  a  rail  inside  the  box;  p/,  plates;  /,  pin  which  holds  the 
front  plate  in  place.  (Copy  of  fig.  3  in  Boutan,  1898.) 


56 


BULLETIN    OF    THE    BUREAU    OF    FISHERIES. 


This  apparatus,  which  used  plates  18  by  24  cm.  (approximately  7  by  9  inches), 
was  so  heavy  that  it  required  three  men  to  handle  it  easily  in  air.  On  shipboard  it 
was  handled  by  a  tackle  and  swinging  boom.  It  was  first  lowered  into  the  hold, 
which  could  be  closed  light  tight.  There  the  plates  were  put  into  the  plate  holder  and 
this  was  set  at  the  division  of  the  scale  previously  decided  upon.  The  box  was  then 
closed  water-tight  by  screwing  the  cover  in  place.  To  remove  the  moisture  from 
the  air  within  the  box  and  thus  prevent  its  condensation  on  the  lens  and  other  parts 
within,  a  wide-mouthed  bottle  containing  quick  lime  was  kept  in  the  box  during 
the  intervals  when  it  was  not  immersed.  The  apparatus  was  then  hoisted  from  the 
hold,  swung  outboard  and  lowered  to  the  operator,  who  had  meantime  descended  in 
the  diving  suit  and  selected  the  point  at  which  the  photograph  should  be  made.  It 
was  not  very  difficult  for  the  operator  to  handle  the  apparatus  wrhen  it  was  sub- 


FIG. 6.— Showing  Boutan's  method  of  obtaining  instantaneous  photographs  of  fish  with  his  third  ap- 
paratus.   (Copy  of  fig.  7  in  Boutan,  1898.) 

merged,  since  it  was  then  buoyed  up  by  the  water.  It  was  found  easier  to  move  it 
about  when  it  was  suspended  by  means  of  a  rope  to  a  cask  floating  at  the  surface. 
The  method  of  using  the  camera  for  photographing  fish  is  shown  in  figure  6. 
The  camera,  previously  set  for  objects  at  a  distance  of  2.5  meters,  was  placed  on 
a  sand  bottom  at  a  depth  of  3  meters.  Here  it  was  either  allowed  to  rest  on 
the  bottom  on  the  legs  attached  to  it  or  was  supported  above  the  bottom  on  a 
heavy,  four-legged  iron  frame.  The  camera  rested  on  a  platform  within  this  frame 
and  the  platform  might  be  so  adjusted  that  the  camera  could  be  set  at  various 
heights  and  pointed  at  various  angles  up  or  down.  At  a  distance  of  2.8  meters 
from  it  was  set  up  obliquely  a  large  white  screen  of  painted  canvas  stretched  on  an 
iron  frame  provided  with  feet.  This  screen  served  as  a  background  for  the  fish. 
To  attract  the  fish  the  operator  then  placed  in  front  of  the  screen  at  a  distance  of 
about  two  meters  a  bait  of  crushed  sea-urchins  and  annelids.  He  then  pointed  the 
camera  by  means  of  the  sight  on  top  and  waited  until  the  fish,  attracted  by  the 
bait,  were  in  such  a  position  as  to  be  in  focus,  when  by  means  of  the  handle  at  the 


U  N  \  V  . 


PHOTOGRAPHY  OF  AQUATIC  ANIMALS, 


57 


front  he  made  the  exposure.  The  plate  was  then  changed  and  several  exposures 
made  in  succession.  The  screen  was  useful  as  affording  a  contrasting  background 
but  was  not  considered  necessary,  since  very  clear  negatives  were  obtained  of  fish 
viewed  against  the  sand  or  ooze  bottom.  One  of  the  photographs  of  fish  taken 
against  a  screen  background  is  reproduced  by  heliogravure  in  Boutan's  memoir  of 
1898.  Though  the  fish  were  in  motion,  the  outlines  of  most  of  them  appear  sharp 
against  the  screen,  evidence  that  the  picture  was  instantaneous.  The  fish  are, 
however,  unfortunately  almost  wholly  lacking  in  detail.  The  time  of  the  exposure 
is  not  stated,  but  it  was  clearly  too  short  to  give  detail  in  the  shadows. 

In  figure  7  is  shown  a  method  adopted  by  Boutan  for  operating  the  camera 
from  a  boat  by  means  of  a  string.     In  this  case  the  apparatus  was  first  placed  in 


FIG.  7. — Showing  Boutan's  method  of  operating  his  third  apparatus  from  a  boat  by  means 
of  a  string.    A  diver  is  being  photographed.    (Copy  of  fig.  8  in  Boutan,  1898.) 

position  by  the  diver,  who  then  withdrew  to  the  distance  for  which  the  camera  was 
focused.  The  operator,  who  could  observe  the  procedure  from  the  boat,  then  pulled 
the  string.  The  resulting  picture,  which  is  reproduced  in  Boutan  (1898) ,  is  excellent. 
Subsequently  exposures  were  made  from  the  surface  by  using  a  shutter  controlled 
by  an  electro-magnet. 

BOUTAN'S  METHODS  OF  ARTIFICIAL  ILLUMINATION. 

Besides  his  camera,  Boutan  (1893)  describes  an  apparatus  for  using  a  mag- 
nesium flash-light  beneath  the  surface  of  the  water.  He  succeeded  subsequently 
in  taking  good  instantaneous  pictures  at  a  depth  of  3  meters  without  artificial 


58 


BULLETIN    OF   THE   BUKEATJ   OF   FISHERIES. 


light,  and  estimated  that  in  good  weather  it  would  be  possible  to  do  this  at  depths 
of  7  or  8  meters. 

Although  his  flash-light  apparatus  proved  to  be  unnecessary  in  shallow  water 
and  was  subsequently  abandoned  as  cumbersome  and  dangerous,  it  merits  a 
word  of  description.  His  figure  of  it  is  reproduced  in  figure  8.  In  its  final  form  it 
consisted  of  a  cask  of  about  200  liters  capacity  closed  at  both  ends,  but  with 
the  lower  end  perforated  by  holes  to  permit  the  entrance  of  sea  water.  A  bell  jar 
of  5  or  6  liters  capacity  is  held  tightly  against  the  upper  end  of  the  cask  by  means 
of  the  adjustable  frame  shown  in  the  figure.  The  cavity  of  the  jar  communicates 
freely  through  many  openings  with  that  of  the  cask,  and  both  are  filled  with  air. 

Within  the  bell  jar  is  an  alcohol  lamp,  and  at  the 
side  of  this  is  a  metal  reservoir  (not  shown  in  the 
figure),  covered  with  asbestos  and  filled  with  mag- 
nesium powder.  One  end  of  a  metal  tube  opens 
opposite  the  middle  of  the  flame  of  the  alcohol 
lamp  (shown  lighted  in  the  figure)  and  communi- 
cates freely  with  the  reservoir  above.  The  other 
end  of  the  tube  extends  into  the  cask,  and  is  there 
connected  to  a  rubber  tube  which  extends  through 
the  side  of  the  cask  (at  C  in  fig.  8)  and  ends  in 
a  large  rubber  bulb.  To  use  the  apparatus,  the 
reservoir  is  filled  with  magnesium  powder  and 
the  alcohol  lamp  lighted,  then  the  bell  jar  is 
fastened  in  place  and  the  cask,  heavily  weighted 
at  the  bottom,  is  lowered  into  the  water  and  set 
wherever  needed.  The  air  in  the  bell  jar  and  cask 
is  enough  to  keep  the  alcohol  lamp  burning  for 
some  time.  To  produce  the  flash  it  is  merely 
necessary  to  press  the  bulb,  when  the  magnesium 
powder,  which  has  fallen  from  the  reservoir  into 
the  tube,  is  blown  against  the  flame  from  the  end 
of  the  tube  and  ignited.  This  operation  may  be 
repeated  as  long  as  the  lamp  remains  burning  and 
the  reservoir  contains  magnesium.  It  is  of  course 
necessary  to  operate  the  shutter  of  the  camera 
simultaneously  with  the  flash. 
Boutan  (1900)  describes  and  illustrates  another  illuminating  apparatus  which 
consists  of  two  powerful  arc  lamps  inclosed  in  water-tight  jackets  of  heavy  metal, 
designed  to  withstand  the  pressure  of  the  water  at  a  depth  of  50  meters  or  more. 
Each  jacket  was  pierced  by  an  opening  into  which  was  fitted  a  condensing  lens, 
by  which  the  emerging  light  was  concentrated  upon  the  object  to  be  photographed. 
The  two  lamps  were  rigidly  attached  to  the  camera  support  and  were  supplied, 
through  a  cable,  with  current  from  storage  batteries  on  board  the  boat.  The 
same  cable  carried  also  an  insulated  wire  through  which  an  electro-magnet 
actuating  the  shutter  of  the  camera  could  b'e  controlled.  The  camera  with  lamps 
attached  was  lowered  into  the  water.  When  the  camera  was  on  the  bottom  the 
lamp  circuit  was  closed  by  means  of  a  switch  on  board  the  boat,  and  when  it  was 


FIG.  8. — Boutan's  apparatus  for  using  a  mag- 
nesium flash-light  under  water.  The  reser- 
voir for  the  magnesium  powder,  the  rubber 
bulb,  and  th«  weights  used  to  steady  the  ap- 
paratus are  not  shown  in  the  figure.  (Copy 
of  fig.  3  in  Boutan,  1893.) 


PHOTOGRAPHY  OF  AQUATIC  AWIMAU8,  59 

seen  that  the  lamps  were  working,  the  shutter  was  operated  from  the  boat.  In 
this  way  good  photographs  of  gorgonias  were  obtained  at  night  at  a  depth  of  6 
meters,  with  an  exposure  of  five  seconds.  It  is  not  necessary  that  the  diver  should 
descend  to  place  the  lamp  in  position.  The  same  apparatus  was  worked  successfully 
at  a  depth  of  50  meters,  in  this  case  the  apparatus  not  being  allowed  to  rest  on  the 
bottom,  but  being  held  suspended  from  a  cable  at  some  distance  from  the  bottom. 
The  object  photographed  was  a  canvas  screen  rigidly  attached  by  rods  to  the  camera 
support  at  such  a  distance  from  the  lens  as  to  be  sharply  focused.  When  the 
apparatus  was  brought  to  the  surface  it  was  found  that  one  of  the  lamps  had  failed 
to  withstand  the  pressure  so  that  its  jacket  was  filled  with  water.  With  lamps 
and  camera  constructed  to  withstand  the  pressure  at  great  depths,  Boutan  believes 
that  an  apparatus  of  this  sort  may  be  used  at  depths  to  which  light  does  not 
penetrate.  The  apparatus  may  of  course  be  used  by  a  diver  at  depths  of  40  meters 
or  less,  and  the  camera  may  then  be  directed  at  any  desired  object;  but  at  greater 
depths  a  diver  can  not  work,  and  the  apparatus  must  then  of  course  be  let  down  at 
random,  to  photograph  only  what  chances  to  be  in  the  range  of  its  lens. 

Boutan's  work  has  the  great  merit  of  having  demonstrated  that  it  is  possible 
at  a  depth  of  3  meters  to  obtain  good  instantaneous  pictures  by  the  light  of  the 
sun  and  without  the  use  of  artificial  light.  He  showed  further  that  his  apparatus 
with  electric  illumination  could  be  immersed  and  operated  from  outside  the 
water  at  depths  as  great  as  50  meters.  For  work  at  great  depths  or  by  artificial 
light  no  better  apparatus  is  known.  The  faults  of  it,  for  work  in  shallow  water  or 
at  any  depth  to  which  a  diver  can  descend,  are  (1)  its  great  bulk  and  weight,  and  (2) 
the  fact  that  it  can  not  be  focused  under  water.  It  can  not  be  carried  about  freely, 
and  for  use  it  must  be  set  on  the  bottom  at  a  known  distance  from  the  object  to  be 
photographed  and  must  then  be  sighted  at  that  object.  It  is  unfortunate  that 
for  work  in  shallow  water  Boutan  did  not  make  use  of  the  principle  of  the  twin 
camera  or  the  reflecting  camera,  for  by  using  either  of  these  devices  he  could  have 
made  an  apparatus  that  was  portable  and  that  could  have  been  focused  under  water. 
He  could  thus  have  carried  his  camera  about  as  one  carries  detective  cameras  and 
could  have  photographed  submarine  objects  either  while  wading  with  his  head 
above  water  or  hi  moderate  depths  while  on  the  bottom  in  a  diver's  suit. 

BRISTOL'S  SUBAQUATIC  CAMERA. 

That  such  a  method  is  feasible  and  that  it  may  yield  better  results  than 
those  obtained  by  Boutan  was  suspected  as  early  as  1898  by  Prof.  C.  L.  Bristol, 
who  immediately  began  work  on  a  submarine  photographic  apparatus.  Nothing 
has  as  yet  been  published  concerning  this  apparatus,  and  the  details  of  its  con- 
struction are  quite  unknown  to  me.  Professor  Bristol  kindly  permits  me,  however, 
to  make  the  following  quotation  from  a  letter  to  me  on  the  subject:  "From  the 
first  I  have  used  a  water- tight  camera  capable  of  submersion  hi  from  10  to  15 
fathoms,  mounted  on  a  tripod  with  a  universal  motion,  arranged  so  as  to  show  the 
picture  on  the  ground  glass  as  well  as  to  focus  the  lens  and  make  the  exposure. 
Moreover,  a  magazine  attachment  permits  me  to  carry  down  several  plates  and  to 
change  them  after  each  exposure  while  under  water.  After  several  seasons'  efforts 
the  apparatus  is  now  very  efficient  and  has  produced  excellent  results.  I  am  not 
yet  ready  to  publish  a  detailed  account." 


60 


BULLETIN    OF   THE   BUREAU   OF   FISHERIES. 


A  NEW  SUBAQUATIC  APPARATUS. 

When  a  camera  for  subaquatic  use  is  made  after  the  ordinary  type  the  box 
must  be  securely  closed  before  submerging  it  in  order  to  protect  the  lens  and  the 
plates  from  the  action  of  the  water.  While  the  camera  is  under  water  it  is  not 
possible  to  remove  the  plates  or  plate  holder  in  order  to  substitute  a  ground  glass 
for  them.  It  is  therefore  impossible  to  focus,  and  the  camera  must  be  adjusted  to 
the  desired  focus  before  immersing  it.  This  was  the  method  adopted  by  Boutan 
in  his  third  apparatus.  It  would  be  possible  to  construct  a  camera  that  might  be 
focused  under  water  by  means  of  a  focusing  scale  such  as  is  provided  in  those  hand 
cameras  arranged  to  be  focused  without  the  use  of  a  ground  glass,  the  operator 
estimating  the  distance  of  the  object  and  then  setting  the  camera  for  a  corresponding 

division  on  the  focusing  scale.  This 
method  is  of  value  for  more  distant  ob- 
jects and  with  rather  slow  lenses  of 
great  focal  depth.  When  very  rapid 
lenses  are  focused  on  near  objects  only 
those  objects  are  in  focus  that  lie  nearly 
in  one  plane.  Thus  a  very  accurate  ad- 
justment  of  the  camera  is  necessary  in 
order  to  bring  any  near  obj  ect  into  sharp 
focus,  and  this  is  not  possible  when  the 
distance  of  the  obj  ect  must  be  estimated 
and  the  focusing  accomplished  by  means 
of  a  scale.  In  subaquatic  photography 
the  objects  to  be  photographed  are  all 
near  and  if  instantaneous  work  is  to  be 
done  the  lens  must  be  very  rapid.  It 
is  therefore  important  to  be  able  to  focus 
accurately  on  the  ground  glass  under 
water,  and  this  might  be  accomplished 
by  using  two  identical  cameras  (twin 
camera)  united  so  as  to  form  one  instru- 
ment. One  of  these  contains  the  plates 
and  has  a  lens  provided  with  a  shutter. 
The  other  camera  carries  the  ground  glass.  The  same  focusing  mechanism  operates 
both  cameras,  so  that  when  a  sharp  image  is  formed  on  the  ground  glass  of  the  one  an 
identical  image  strikes  the  sensitive  plate  in  the  other  when  the  shutter  is  operated. 
One  of  the  cameras  serves  merely  as  a  focusing  finder  of  full  size.  A  camera  of  this 
type  properly  constructed  of  metal  could  undoubtedly  be  used  successfully  under  water, 
though  it  has  the  disadvantage  of  being  unnecessarily  cumbersome  and  expensive. 

THE    CAMERA. 

All  of  the  advantages  of  the  twin  camera  are  to  be  had  by  using  a  reflecting 
camera,  which  is  at  the  same  time  both  lighter  and  less  expensive.  The  principle 
of  the  reflecting  camera  is  shown  in  figure  9,  which  represents  diagrammatically 


FIG.  9. — A  reflecting  camera  shown  in  section,  with  magazine 
plate  holder  attached,  gl,  ground  glass;  h  h',  hood;  Z,lens;  m, 
mirror  in  position  during  focusing;  m',  mirror,  showing  position 
during  exposure;  p,  sensitive  plate;  r  and  r',  rollers  of  focal 
plane  shutter;  s,  the  shutter;  si,  slot  in  shutter;  x,  hinge  on 
which  mirror  turns;  y  y  y',  ray  of  light  traversing  the  lens  and 
reflected  from  the  mirror  to  the  ground  glass. 


PHOTOGRAPHY    OF    AQUATIC    ANIMALS.  61 

such  a  camera  in  longitudinal  section.  The  ground  glass  (gl)  is  placed,  not  at  the 
back  of  the  camera,  as  is  usual,  but  in  the  top.  The  operator,  holding  the  camera  in 
front  of  him,  looks  in  the  direction  indicated  by  the  upper  arrow,  at  the  ground  glass 
through  the  hood  (h  Ji'),  which  takes  the  place  of  a  focusing  cloth.  The  ulterior  of 
the  camera  contains  a  mirror  (m),  which  extends  from  beneath  the  back  edge  of  the 
ground  glass  downward  and  forward  at  an  angle  of  45°.  The  mirror  is  hinged  at  x 
to  the  top  of  the  camera.  When 'it  is  in  the  position  shown  at  m  in  the  figure  the 
space  between  the  back  of  the  mirror  and  the  back  of  the  camera  is  quite  dark. 
Light  entering  through  the  lens  is  reflected  by  the  mirror  and  strikes  the  ground 
glass,  as  shown  by  the  line  y  y  y' .  The  image  as  seen  on  the  ground  glass  by  the 
operator  looking  down  through  the  hood  is,  on  account  of  the  action  of  the  mirror, 
an  erect  image,  not  an  inverted  image  such  as  one  sees  on  the  ground  glass  in  the 
back  of  an  ordinary  camera.  It  is  also  an  image  of  the  full  size  permitted  by  the 
plate  and  the  lens,  not  a  reduced  image  such  as  one  sees  in  a  finder.  The  shutter 
(s)  is  a  focal  plane  shutter  situated  at  the  back  of  the  camera  just  in  front  of  the 
plate  (p).  Such  a  shutter  is  essentially  a  roller  curtain  of  black  cloth  with  a  slot  (si) 
across  it  at  one  point.  The  width  of  the  slot  may  be  regulated.  The  shutter  is 
wound  upon  an  upper  roller  (r)  until  the  slot  is  upon  the  roller.  The  exposure  is 
made  by  causing  the  curtain  to  unwind  from  the  upper  roller  (r)  and  wind  upon  the 
lower  roller  (/)  so  that  the  slot  passes  very  rapidly  across  the  face  of  the  plate. 
The  length  of  the  exposure  depends  on  the  width  of  the  slot  and  the  rate  at  which  it 
moves.  The  rate  may  be  varied  by  changing  the  tension  of  the  spring  which 
actuates  the  lower  roller.  The  operator  holds  the  camera  in  front  of  him  with  both 
hands  while  he  looks  down  at  the  ground  glass  through  the  opening  in  the  hood. 
With  one  hand  he  focuses.  When  the  object  appears  in  sharp  focus  and  hi  the 
desired  position  on  the  ground  glass,  he  presses  a  button  with  the  other  hand. 
This  causes  the  mirror  to  swing  on  its  hinge  to  the  position  shown  by  the  dotted  out- 
line m'  beneath  the  ground  glass.  In  this  position  the  mirror  excludes  light  which 
might  otherwise  enter  the  camera  through  the  ground  glass.  At  the  same  time  the 
change  in  position  of  the  mirror  permits  the  light,  which  was  before  reflected  to 
the  ground  glass,  to  fall  upon  the  plate.  The  adjustment  is  such  that  an  image 
which  is  in  sharp  focus  on  the  ground  glass  will  be  in  sharp  focus  on  the  plate  when 
the  mirror  changes  position.  The  image  does  not  actually  strike  the  plate  so  long 
as  the  shutter  is  wound  upon  either  roller.  Before  the  instrument  is  to  be  used  the 
shutter  is  wound  on  the  upper  roller.  When  the  mirror  in  swinging  upward  reaches 
the  position  m'  the  shutter  is  released  from  the  upper  roller  and  taken  up  on  the 
lower  roller.  As  the  slot  passes  across  the  plate  from  above  downward,  the  image 
falls  through  the  slot  onto  the  plate  in  successive  strips  corresponding  to  the  width 
of  the  slot. 

The  advantages  of  this  form  of  camera  are  the  folio  wing : 

1.  The  operator  sees  a  full  sized,  erect  image  on  the  ground  glass,  while  at  the 
same  time  the  sensitive  plate  is  in  position  for  exposure. 

2.  He  is  able  to  focus  and  to  regulate  the  position  of  the  image  on  the  ground 
glass  up  to  the  instant  of  exposure. 

3.  Much  more  rapid  exposures  may  be  made  with  the  focal  plane  shutter  than 
with  the  ordinary  diaphragm  shutter.     The  diaphragm  shutter  occupies  a  considerable 


62  BULLETIN    OF    THE    BUREAU  _  OF    FISHERIES. 

time  in  opening  and  closing,  and  during  the  period  of  operation  prevents  the  light 
from  passing  through  the  full  opening  of  the  lens.  If  the  time  from  the  instant 
a  diaphragm  shutter  begins  to  open  until  it  is  closed  again  is  one  one-hunredthd 
of  a  second,  then  a  considerable  part  of  this  time  (usually  about  40  per  cent)  is 
occupied  by  the  opening  and  closing.  The  shutter  is  then  wide  open  and  the  lens 
working  at  its  full  opening  during  only  a  fraction  of  the  one  one-hundredth  of  a  second. 
With  the  focal  plane  shutter,  on  the  other  hand,  if  the  slot  requires  a  hundredth 
of  a  second  to  pass  a  given  point  on  the  plate,  the  lens  may  be  wide  open  during  the 
whole  of  that  time,  so  that  all  the  light  that  the  lens  is  capable  of  passing  reaches 
the  plate  during  the  whole  of  the  exposure.  For  this  reason  much  more  rapid 
exposures  may  be  made  with  the  focal  plane  shutter  than  with  the  diaphragm  shutter. 
Various  forms  of  reflecting  camera  are  in  the  market,  and  it  is  possible  to 
obtain  a  magazine  plate  holder,  which  carries  12  plates,  arranged  to  be  changed 
without  removing  the  plate  holder  from  the  camera  or  inserting  the  dark  slide. 
Such  a  camera,  with  the  magazine  holder,  is  shown  diagrammatically  in  section  in 
figure  9.  It  is  surprising  that  Boutan,  when  he  was  seeking  some  means  of  focusing 
his  camera  under  water,  did  not  make  use  of  the  idea  of  the  reflecting  camera;  for 
by  merely  inclosing  such  a  camera  in  a  water-tight  metal  box  and  arranging  it  to 
be  operated  from  outside  the  box,  he  would  have  had  a  portable  apparatus  capable 
of  being  manipulated  under  water  almost  as  readily  as  on  land.  A  reflecting 
camera  was  manufactured  in  New  York  as  early  as  1886,  and  was  advertised  at 
that  time  and  represented  by  a  Paris  agent. 

THE    WATER-TIGHT    BOX. 

A  5  by  7  camera  of  the  type  just  described,  with  a  magazine  holder  for  12  plates, 
was  used  by  the  writer  to  obtain  submarine  photographs  at  Tortugas,  Fla.,  during 
the  season  of  1907.  The  box  (fig.  2,  pi.  v)  to  contain  the  camera  was  made  of  gal- 
vanized iron  by  a  tinsmith.  It  measures  about  17  inches  long,  9  inches  high,  and  10 
inches  wide.  The  front  is  closed  by  a  square  of  plate  glass  cemented  with  aquarium 
cement  into  a  groove  formed  in  the  metal.  At  the  top  is  an  opening  large  enough 
to  permit  the  camera  to  pass,  bottom  first,  into  the  box.  To  the  outside  of  the  rim 
of  this  opening  is  soldered  half-inch  square  brass  tubing  jointed  at  the  corners  into 
a  rectangular  frame.  The  upper  surface  of  this  frame  is  made  as  smooth  and  as 
nearly  plane  as  possible.  Eight  brass  screw-bolts  are  soldered  into  holes  drilled 
through  this  frame.  They  occupy  the  positions  shown  in  the  figure  and  the  threaded 
end  of  each  projects  about  three-quarters  of  an  inch  above  the  frame.  The  cover 
consists  of  a  flat  sheet  of  metal  bordered  by  a  frame  of  brass  identical  with  that  on 
the  box.  This  frame  is  perforated  by  eight  openings  through  which  the  screw-bolts 
pass.  From  the  cover  there  arises  an  irregular  truncated  pyramid  of  galvanized  iron, 
which  incloses  the  hood  of  the  camera.  At  the  top  this  is  closed  by  a  piece  of  plate 
glass.  By  means  of  wing  nuts  on  the  screw-bolts  the  cover  may  be  tightly  clamped 
to  the  box,  against  an  intervening  gasket  of  rubber. 

On  the  right  hand  side  of  the  box  is  a  large  milled  head  of  brass  from  which 
a  brass  stem  passes  to  the  interior  through  a  stuffing  box,  which  prevents  the 
entrance  of  the  water  along  the  stem.  At  its  inner  end  the  stem  terminates  in  a 


PHOTOGRAPHY    OF    AQUATIC    ANIMALS.  63 

two-pronged  fork.  The  stem  may  be  pulled  in  and  out  in  the  stuffing  box  through 
a  distance  of  about  three-quarters  of  an  inch.  When  the  stem  is  pushed  in,  the 
prongs  of  the  fork  engage  hi  two  holes  drilled  hi  the  focusing  head  of  the  camera. 
By  turning  the  milled  head  on  the  outside  of  the  box  the  camera  may  then  be 
focused.  On  the  opposite  side  of  the  box  is  a  second  but  smaller  brass  head  from 
which  a  stem  passes  through  a  stuffing  box  to  the  interior  of  the  box,  and  termi- 
nates in  a  flat  disk.  The  disk  lies  opposite  the  release  pin  of  the  camera  by  which 
the  mirror  and  shutter  are  set  in  motion.  A  light  spiral  spring  wound  about  the 
stem  between  the  outer  head  and  the  stuffing  box  keeps  the  stem  thrust  outward 
to  its  full  extent.  Pressure  on  the  outer  head  causes  the  metal  disk  to  strike  the 
release  pin  so  as  to  make  the  exposure. 

In  order  to  use  the  box,  it  is  necessary  to  attach  to  it  a  weight  heavy  enough 
to  submerge  all  but  about  the  upper  6  inches  of  the  hood.  In  the  experimental 
apparatus  used  this  weight  was  made  by  folding  sheet  lead  to  form  a  flat  mass  of 
the  dimensions  of  the  bottom  of  the  box.  The  weight  (not  shown  hi  the  figure) 
was  made  slightly  wedge  shaped  lengthwise  and  was  attached  to  the  bottom  of 
the  camera  by  wires  passing  beneath  it  and  soldered  at  their  ends  to  the  sides  of  the 
box.  As  the  camera  would,  in  use,  usually  be  pointed  slightly  downward,  the 
thicker  end  of  the  weight  was  placed  in  front,  so  that  the  box  floated  with  its  front 
end  somewhat  lower  than  its  back  end. 

USIN'G  THE    APPARATUS. 

The  apparatus  was  used  hi  the  following  manner:  The  magazine  plate  holder 
containing  twelve  plates  was  attached  to  the  camera,  the  mirror  depressed,  the 
shutter  set  at  the  desired  speed  and  width  of  slot,  and  wound.  The  dark  slide  was 
then  drawn  from  the  magazine  holder,  and  the  camera,  thus  made  ready  for  an 
exposure  in  air,  was  placed  in  the  box.  Metal  cleats  soldered  to  the  bottom  of  the 
box  brought  it  always  to  the  same  position.  The  head  on  the  right  of  the  box 
was  then  pushed  in  until  the  fork  engaged  in  the  holes  in  the  focusing  head  of  the 
camera.  The  top  was  then  put  on  the  box  and  clamped  down  by  the  wing  nuts  as 
firmly  as  possible.  The  apparatus  thus  made  ready  was,  when  in  air,  as  heavy  a 
load  as  one  man  could  conveniently  carry.  It  was  carried  to  a  boat  or,  if  it  was  to 
be  operated  near  shore,  to  the  shore.  In  working  with  the  help  of  a  boat  the 
operator  wades  on  or  near  the  coral  reef  with  his  head  and  shoulders  above  the  water. 
The  boat,  with  an  attendant  on  board,  is  anchored  near.  The  operator,  with  the 
help  of  a  water  glass,  now  seeks  a  favorable  place  for  operations.  As  he  moves  about 
the  reef,  the  fish  at  first  seek  shelter  in  the  dark  recesses  of  the  coral  rock,  but  if  he 
selects  a  favorable  place  and  remains  quiet  they  soon  reappear.  They  are  at 
first  wary,  but  soon  grow  bolder  and  after  half  an  hour  or  so  pay  but  little  atten- 
tion to  him.  There  is  a  great  difference  in  wariness  among  different  species  of  fish. 
At  first  only  one  or  two  species  appear,  demoiselles  and  slippery-dicks  usually,  then 
the  number  of  species  gradually  increases  until  the  shyest  butterfly-fish  and  parrots 
come  within  6  or  8  feet  of  the  operator.  He  then  has  the  camera  passed  to 
him  from  the  boat.  It  floats  with  the  upper  part  of  the  hood  protruding  and 
(fig.  1 ,  pi.  v)  may  be  easily  turned  toward  any  point  on  the  horizon  or  even  tilted  so  as 


64  BULLETIN    OF    THE    BUREAU    OF    FISHERIES. 

to  be  pointed  at  a  considerable  angle  upward  or  downward.  The  operator  has  now 
merely  to  direct  the  camera  at  the  fish,  while  he  focuses  with  his  right  hand.  He 
must  often  wait  some  time  before  the  fish  come  to  the  point  selected  or  assume 
the  desired  attitude.  Often  they  may  be  enticed  by  throwing  in  a  bait  of  crushed 
sea  urchins  or  pieces  of  crawfish.  They  are  in  constant  motion  so  that  he  must 
as  constantly  focus.  He  often  misses  a  long-awaited  opportunity  because  the  fish 
moves  on  or  takes  a  wrong  attitude  before  he  has  had  time  to  focus  sharply;  but 
when  the  favorable  time  comes  he  presses  the  release  stem  and  the  exposure  is  made. 

The  apparatus  must  then  be  lifted  into  the  boat,  the  cover  removed  from  the 
box,  and  the  camera  taken  out  in  order  to  reset  the  shutter  and  change  the  plate. 
It  is  best  that  all  this  be  done  by  the  attendant  who  remains  in  the  boat,  as  the 
operator  is  thus  left  free  to  watch  the  fish,  while  at  the  same  time  the  fish  are  not 
unduly  frightened  by  the  sudden  movements  that  he  would  make  in  lifting  the 
camera.  With  care,  however,  one  person  may  do  all  the  work  necessary.  He 
may  anchor  the  boat  near,  pull  it  to  him  by  means  of  a  line,  lift  in  the  camera,  and 
make  all  the  necessary  adjustments  while  he  himself  remains  in  the  water.  If  the 
work  is  done  near  shore,  the  camera  may  be  carried  to  shore  after  each  exposure. 
In  that  case  an  assistant  is  very  desirable,  since  the  return  of  the  operator  after 
each  absence  disturbs  the  fish.  Moreover,  when  near  shore  he  is  moving  over  the 
rock  or  sand  bottom,  not  over  the  clean  upper  surface  of  the  reef,  and  every  con- 
siderable movement  stirs  up  the  bottom  sediment  so  that  some  time  must  pass 
before  the  water  is  again  clear  enough  to  permit  an  exposure  to  be  made.  If  an 
assistant  is  available,  he  may  stand  at  a  considerable  distance  from  the  operator, 
who  sends  the  camera  box  to  him  through  the  water  by  a  quick  shove.  The  assistant, 
after  he  has  carried  it  ashore  and  readjusted  it,  returns  it  in  the  same  way. 

The  opening  of  the  box  after  each  exposure  occupies  some  little  time,  and 
during  this  time  favorable  opportunities  to  make  exposures  are  often  lost.  It 
would  be  better  if  a  mechanism  were  provided  by  which  the  plates  might  be  changed 
without  opening  the  box,  which  would  then  remain  in  the  water  until  twelve  expo- 
sures had  been  made.  Nevertheless  it  is  possible  with  the  apparatus  described  to 
make  twelve  exposures  on  coral-reef  fish  in  about  two  hours,  including  the  lifting 
of  the  box  from  the  water  between  exposures  and  opening  it  to  change  plates. 
Any  form  of  reflecting  camera  may  be  used  and  any  form  of  plate  holder.  Films 
may  also  be  used  in  rolls  or  packs.  In  addition  to  the  reflecting  camera  the  operator 
needs  only  a  metal  box  of  the  structure  described  and  of  a  form  suited  to  his  camera. 
This  may  be  made  by  any  good  tinsmith  at  a  cost  of  a  few  dollars. 

A  camera  of  this  type  inclosed  in  a  suitable  box  may  be  held  in  the  hand  while 
in  use,  or  it  may  be  set  upon  a  tripod  of  heavy  iron,  such  as  is  shown  in  figure  4. 
Such  a  tripod  would  best  have  a  top  of  the  form  shown  in  figure  2,  but  made  of  heavy 
iron  instead  of  wood.  The  operator  may  descend  in  a  diving  suit,  as  Boutan  did, 
and  use  the  camera  at  the  bottom  in  deep  water  either  while  holding  it  in  the  hand 
or  while  it  is  supported  on  a  tripod.  There  should  be  no  difficulty  in  focusing 
while  looking  through  the  plate-glass  window  of  a  diver's  casque.  For  work  on  the 
coral  reefs  of  the  Tortugas,  however,  the  writer  has  found  that  everything  may  be 
done  from  the  surface,  so  that  a  diver's  suit  is  quite  unnecessary.  He  is  told  that 
similar  conditions  exist  at  the  Bermudas.  From  his  own  experience  in  fresh  water 


PHOTOGRAPHY    OF    AQUATIC    ANIMALS.  65 

he  is  inclined  to  believe  that  probably  all  the  photographic  work  that  it  is  desirable 
to  do  there  may  be  done  without  the  use  of  a  diver's  suit.  The  occasions  on  which 
such  a  suit  is  really  necessary  for  work  in  either  fresh  or  salt  water  are  probably 
extremely  rare. 

If  the  objects  to  be  photographed  are  motionless,  or  nearly  so,  time  exposures 
may  be  made  with  this  apparatus  by  suitably  adjusting  the  camera  before  placing 
it  in  the  box.  For  this  use  it  is  desirable  to  add  to  the  box  a  third  rod  working 
through  a  stuffing  box  and  so  placed  that  by  means  of  it  the  shutter  may  be  released 
independently  of  the  mirror. 

Two  photographs  made  by  the  method  here  described  are  reproduced  on  plate 
ii.  In  figure  1,  plate  i,  a  butterfly-fish  (Chaetodon  ca pi stratus)  with  a  stripe  through 
the  eye  and  an  eye-like  spot  on  the  tail  is  seen  over  a  flat  expanse  of  coral  ( Meandrina) 
and  at  the  base  of  a  large,  branching  gorgonian.  The  photograph  was  taken  while 
the  fish  was  in  rapid  movement.  The  expanded  polyps  may  be  seen  on  the  gorgo- 
nian just  above  the  fish  and  elsewhere.  Figure  2,  plate  n,  shows  a  group  of  parrot 
fishes,  of  at  least  three  species,  and  several  surgeons  against  a  background  of  branch- 
ing gorgonians  on  a  ledge  of  rock.  Near  the  center  is  a  blue  and  yellow  striped 
grunt,  Hsemulon  Jlavolineatum.  At  the  left  of  this  is  a  blue  parrot-fish,  CaUyodon 
cwuleus.  At  the  right  of  the  grunt  is  a  green  parrot-fish,  CaUyodon  vetula,  about 
18  inches  long.  Beneath  the  green  parrot  is  a  mottled  parrot-fish  (Sparisoma?}. 
Above  the  grunt  is  a  second  mottled  parrot  and  to  the  left  of  this  a  third.  At 
the  extreme  left  are  two  surgeons,  Ilepatus  Jiepatus:  a  third  is  seen  below  the  green 
parrot.  Above  the  green  parrot,  in  the  background,  is  a  purple  sea  fan,  RJiipi- 
doglossa.  In  most  of  the  fish  the  details  of  the  markings  and  the  outlines  of  the 
scales  are  clearly  seen. 

These  photographs  were  taken  in  water  about  4  feet  deep  with  a  Goerz  II.  B. 
lens  at  a  speed  of  f  5.  The  exposure  was  3*5  second  with  Seeds  P.  orthochro- 
matic  plate  and  a  no.  3  graphic  color  screen.  The  plates  were  fully  timed  and 
were  developed  rapidly  with  a  strong  pyro  developer. 

The  apparatus  used  by  the  writer  was  experimental  only  and  was  meant 
for  temporary  use.  It  is  easy  to  suggest  improvements,  the  greatest  of  which 
would  be  a  magazine  plate  holder  for  at  least  twelve  plates  and  capable  of  being 
operated  from  outside  the  box  which  incloses  the  camera.  There  appears  to  be  no 
such  holder  on  the  market.  Magazine  holders  provided  with  a  bag  can  not  be 
used  even  though  the  leather  bag  of  the  plate  holder  be  covered  with  a  rubber  bag 
so  attached  to  the  box  inclosing  the  camera  that  the  water  can  not  enter,  for  the 
pressure  of  the  water  is  such  that  even  when  the  box  is  but  partly  immersed  the 
rubber  bag  is  forced  into  the  box  through  the  opening  to  which  it  is  attached  and 
the  holder  can  not  then  be  manipulated.  This  difficulty  would  be  increased  if  an 
attempt  were  made  to  use  the  apparatus  at  a  greater  depth.  What  is  needed  is  a 
magazine  plate  holder  that  presents  a  rigid  exterior  everywhere  and  that  may  be 
operated  from  the  outside  of  the  box  by  means  of  rods  passing  to  the  inside  through 
stuffing  boxes. 

The  box  can  be  improved  by  reducing  to  its  lowest  limit  the  number  of  screws 
used  to  fasten  the  cover,  for  if  but  one  or  two  screws  had  to  be  loosened  to  open  the 
box  much  time  would  be  saved  in  changing  plates. 

B.  B.  F.  1907—5 


66  BULLETIN    OF   THE   BUKEAU   OF   FISHERIES. 

A  part  of  the  weight  attached  to  the  bottom  of  the  box  should  be  movable, 
so  that  it  could  be  fastened  either  toward  the  front  or  toward  the  back.  In  this  way 
the  box  could  be  made  to  float  with  the  lens  pointed  at  a  considerable  angle  toward 
the  bottom  or  toward  the  surface  of  the  water.  The  operator  would  then  be  spared 
the  very  considerable  effort  necessary  to  hold  the  box  in  position  when  the  lens 
is  directed  much  above  or  below  the  plane  in  which  the  box  floats. 

The  purpose  of  the  writer  has  been  to  utilize  an  ordinary  reflecting  camera 
for  subaquatic  work  by  inclosing  it  in  a  suitable  water-tight  box  without  in  any  way 
lessening  its  availability  for  use  in  air  when  removed  from  the  box.  For  use 
exclusively  in  water  it  would  be  best  to  design  a  reflecting  camera  that  could  be 
immersed  directly  in  water  without  first  inclosing  it  in  a  box.  Such  a  camera 
would  have  to  be  of  metal,  water-tight,  and  would  need  to  have  the  lens  covered 
by  a  plate  of  glass.  It  would  need  to  have  only  a  small  opening  at  the  back  on 
one  side  for  inserting  and  removing  the  plates.  Such  an  opening  could  probably 
be  readily  closed  by  a  cover  held  in  place  by  one  or  two  screws.  A  camera  of  this 
sort,  if  made  rigid  enough  to  withstand  the  pressure  of  the  water  at  even  moderate 
depths,  would  be  too  heavy  for  convenient  use  in  air.  It  would  have  the  advan- 
tage of  simplicity  and  increased  ease  of  manipulation. 

SOME  LIMITATIONS  OF  SUBAQUATIC  PHOTOGRAPHY. 

Turbidity  of  the  water  sets  a  limit  to  subaquatic  photography  very  much  as 
fog  or  rain  or  partial  darkness  restricts  photography  in  air.  The  water  must  be 
clear — that  is,  apparently  free  from  particles  in  suspension.  If  instantaneous 
work  is  to  be  attempted  the  water  must  be  free  from  the  reddish  color  that  often 
tinges  fresh-water  lakes  and  streams,  for  the  tinge  of  red  or  yellow  acts  as  a  color 
screen  and  greatly  lengthens  the  time  necessary  for  the  exposure. 

When  one  looks  from  the  air  into  the  ocean  water  at  the  Tortugas  or  Bermudas, 
or  into  the  fresh  water  of  some  of  our  northern  lakes,  it  appears  to  be  as  clear  as 
the  air  itself.  When  the  surface  is  undisturbed,  objects  on  the  bottom  at  depths 
of  10  to  20  feet  appear  with  as  much  clearness  as  though  seen  through  air  alone. 
The  impression  is  created  that  such  water  is  actually  as  clear  as  air,  and  that  the 
water  would  offer  no  .more  obstruction  to  the  vision  of  one  beneath  it  than  air 
itself.  To  test  this  impression  the  writer  constructed  a  reflecting  water  glass 
somewhat  like  a  reflecting  camera  without  the  lens.  It  was  a  metal  tube  2  feet 
long,  and  contained  two  parallel  mirrors,  set  at  an  angle  of  45°  with  its  long  axis, 
and  placed  one  at  each  end.  By  putting  one  end  of  this  with  its  mirror  beneath 
the  surface  and  looking  into  the  mirror  at  the  other  end,  he  obtained  a  view  of  the 
subaquatic  landscape  such  as  a  diver  obtains  when  he  looks  about  him  through 
the  glass  window  in  his  casque.  It  is  surprising  to  find  how  limited  is  the  range 
of  one's  vision  under  these  circumstances.  Even  in  the  clear  sea  water  about 
tropical  islands  objects  at  a  distance  of  20  feet  begin  to  appear  indistinct,  and 
beyond  that  distance  they  fade  into  a  bluish  haze  which  constitutes  the  back- 
ground. This  haze  has  not  the  effect  of  fog  or  smoke  or  twilight.  It  is  as  though 
the  near  distance  were  limited  on  all  sides  by  walls  of  bluish  translucent  quartz 
which  merged  into  the  near  water.  From  these  walls  the  fish  emerge  and  grow 


PHOTOGRAPHY    OF    AQUATIC    ANIMALS.  67 

rapidly  more  distinct  as  they  approach.  Into  them  they  vanish  suddenly  as  they 
recede. 

Subaquatic  photographs  show  the  same  lack  of  distance  that  so  impresses  the 
eye.  Thus  in  the  photographs  shown  on  plate  n  the  distance  appears  indistinct, 
partly  because  the  objects  in  it  are  out  of  focus,  but  chiefly  because  they  are  enveloped 
in  the  bluish  translucence  mentioned  above.  It  is  therefore  impossible  under  water 
to  photograph  objects  at  any  considerable  distance.  To  the  photographer  who 
is  unfamiliar  with  the  aspect  of  the  subaquatic  landscape  this  lack  of  distance  in 
photographs  of  it  seems  a  defect.  But  to  the  artist  or  naturalist  who  has  seen  things 
as  they  look  to  one  beneath  the  water  it  is  really  a  merit,  since  it  shows  these  things 
as  they  are. 

The  source  of  this  lack  of  distance  is  probably  double.  It  is  due  in  part  to  the 
fact  that  even  the  clearest  water  contains  very  many  bodies  in  suspension,  living 
organisms,  and  inorganic  and  organic  particles.  These,  like  dust  in  the  atmosphere, 
interfere  with  distance  vision.  It  is  due  also  in  part  to  the  reflection  of  the  light 
from  the  surface  of  the  water.  Light  which  has  entered  the  water  from  above 
strikes  upon  and  illuminates  various  bodies  beneath  the  surface.  From  these  a  part 
of  it  is  reflected  to  the  surface  of  the  water  again.  If  it  strikes  the  surface  at  an 
angle  of  more  than  48°  35'  with  the  vertical  it  is  totally  reflected  and  passes  again 
into  the  water.  Here  it  again  strikes  some  submerged  body  and  is  again  in  part 
reflected  to  the  surface  and  here  again  in  part  re-reflected-  Thus  shallow  water  is 
traversed  in  every  direction  by  beams  of  light  which  intercross  at  every  angle. 
These  illuminate  the  opaque  particles  floating  in  the  water  and  are  deflected  bv 
reflection.  They  are  also  deflected  by  refraction  through  the  more  transparent 
organisms.  In  this  way  probably  is  produced  the  background  of  bluish-white 
opalescence  which  characterizes  the  subaquatic  landscape.  To  one  who  knows 
that  landscape,  the  background,  hiding  many  mysteries,  adds  to  it  character  and 
beauty.  A  photograph  that  failed  to  show  it  would  be  lacking  in  character.  Boutan 
(1893),  who  discusses  this  subject,  made  use  of  a  blue  color  screen  and  believed  that 
he  obtained  greater  distance  in  his  subaquatic  pictures  by  this  means.  In  his  more 
recent  work  (1900,  p.  283)  he  abandoned  the  use  of  the  color  screen.  He  obtained 
clear  pictures  of  near  objects  by  using  a  shade  above  the  lens,  as  already  described. 
Boutan  appears  never  to  have  obtained  clear  pictures  of  more  distant  objects.  The 
writer  has  made  use  of  an  ordinary  yellow  color  screen  (graphic  no.  3)  but  is  unable 
to  say  with  certainty  that  it  adds  anything  to  the  distance  in  his  pictures.  The 
subject  needs  further  study. 

A  second  characteristic  of  the  subaquatic  photographs  that  strikes  the  photog- 
raphers unpleasantly  is  their  flatness.  Objects  of  all  sorts  appear  lacking  in  thick- 
ness or  rotundity  and  do  not  cast  abrupt  or  heavy  shadows.  This  peculiarity  the 
writer  believes  to  be  due  to  the  reflection  of  light  from  submerged  objects  into  the 
water  at  the  water's  surface.  Light  thus  reflected  on  the  subaquatic  object  from 
the  bottom  beneath  and  from  the  surface  above  and  at  all  angles  takes  out  of  it 
much  of  its  roundness.  It  takes  out  the  shadows  very  much  as  a  photographer  in 
his  studio  may  take  them  out  by  a  suitable  adjustment  of  reflecting  screens.  Along 
with  this  flatness  of  the  individual  objects  in  the  subaquatic  photograph  there  is 
abundance  of  contrast  between  different  parts,  as  may  be  seen  in  plate  I. 


68  BULLETIN    OF    THE    BUREAU    OF    FISHERIES. 

This  lack  of  distance  and  this  flatness  combined  with  contrast,  so  character- 
istic of  the  subaquatic  photograph,  are  not  real  defects.  They  are  rather  truthful 
representations  of  the  conditions  that  actually  obtain.  To  the  photographer 
accustomed  only  to  photographs  made  on  land  they  appear  to  be  defects.  To  one 
who  knows  the  subaquatic  landscape  they  are,  from  the  artistic  standpoint,  sources 
of  beauty.  From  the  scientific  point  of  view  they  undoubtedly  place  limitations  on 
subaquatic  photography. 

LITERATURE  CITED. 

BOUTAN,  L. 

1893.  Memoirs  sur  la  photographic  sous-marine.     Archives  de  Zoologie  expeYimentale  et  gonerale, 

ser.  3,  t.  i,  p.  280-324,  pi.  xvm  and  4  fig. 
1898.  L'instantane  dans  la  photographic    sous- marine.     Comptes    rendus   de   1' Academic   des 

Sciences,  Paris,  t.  cxxvn,  p.  731-733  (Novembre). 
1898a.  L'instante  dans  la  photographic  sous-marine.     Archives  de   Zoologie  experimentale  et 

generale,  ser.  3,  t.  vi,  p.  299-330,  pi.  xx-xxm,  8  fig. 
1900.  La  photographic  sous-marine  et  les  progres  de  la  photographic.     Paris,  1900,  332  p.,  52  fig., 

12  pi. 
FABRE-DOMERGUE. 

1898.  Photographie  d'aquarium.     Photo-Gazette,  vol.  vn  (8). 
JORDAN,  D.  S.,  and  EVERMANN,  B.  W. 

1902.  American  food  and  game  fishes.     573  p.,  illus.     New  York.     (Contains  many  photographs 

from  life  by  A.  Radclyffe  Dugmore.) 
REIGHARD,  JACOB.  • 

1903.  The  natural  history  of  Amia  calva  Linnaeus.     Mark  Anniversary  Volume,  p.  57-109,  pi.  vu. 

(Plate  reproduced  by  lithography  from  colored  photographs  of  Amia.) 
RUDATJX,  L. 

1908.  La  photographie  a  travers  Feau.     La  Nature,  no.  1824,  9  Mai,  1908,  p.  360-363.     (Transla- 
tion in  Literary  Digest  of  June  13,  1908.) 
SAVILLE-KENT,  W. 

1893.  The  Great  Barrier  Reef  of  Australia.     Its  products  and  potentialities.     London,  p.  i-xvm-|- 

1-387.     Photo-mesotype  pi.  I-XLVIII,  chromo  pi.  i-xvi. 
SHUFELDT,  R.  W. 

1898.  The  camera  and  the  aquarium.     Photo  Era,  vol^n,  p.  147-150,  3  fig. 

1899.  Experiments  in  photography  of  live  fishes.     Bulletin  U.  S.  Fish  Commission,  vol.  xix,  1899, 

p.  1-5,  pi.  1-9. 


Bui.  U.  S.  B.  F.  1907. 


PLATE  III. 


-       - 

-     +&*•&!: ".'  -V-i 


FIG.  1 .  PHOTOGRAPH  OF  THE  NEST  OF  A  SMALL-MOUTHED  BLACK  BASS  i  MICROPTERUS  DOLOMIEUj 
TAKEN  WITH  THE  AID  OF  A  SCREEN,  THE  CAMERA  ABOVE  WATER. 


FIG.  2.  BROOK  LAMPREYS  i  LAMPETRA  WILDERI)  ON  THE  NEST,  PHOTOGRAPHED  THROUGH  THE  WATER  GLASS  SHOWN   IN 
FIGURE  2,  PLATE  IV,  IN  ABOUT  8  INCHES  OF  RUNNING  WATER. 


Bui.  U.  S.  B.  F.  1907. 


PLATE  IV. 


FIG.  I.  WATER  GLASS  DESIGNED   BY  THE  WRITER  TO   BE  USED   FOR  OBSERVATION  OR 
PHOTOGRAPHY  OF  OBJECTS  UNDER  WATER. 

The  cover  is  shown  at  the  left. 


FIG.  2.  TWO-FOOT  WATER  GLASS  SUPPORTED  ON  FOUR  LEGS  AND  PROVIDED 
WITH  SCREEN,  AS  USED  FOR  STUDYING  AND  PHOTOGRAPHING  LAMPREYS 
(LAMPETRA  WILDERI). 


Bui.  U.  S.  B.  F.  1907. 


PLATE  V. 


FIG.  I.  PHOTOGRAPH   SHOWING  THE  METHOD  OF  USING  THE  REFLECTING  CAMERA  WHEN 
INCLOSED   IN  THE  WATER-TIGHT  BOX  FOR  SUBAQUATIC  WORK. 

The  upper  part  of  the  box  covering  the  ho<Kl  rises  above  the  surface,  while  the  lower  part,  containing 
the  camera  proper.  i>  under  water.  The  operator  is  looking  into  the  ho»d  through  the  plate  glass 
in  the  top  of  the  box.  With  his  right  hand  he  focuses :  with  his  left  makes  the  exposure. 


FIG.  2.  GALVANIZED-IRON   BOX  WITH  PLATE-GLASS  FRONT,   DESIGNED   BY  THE  WRITER  TO 
CONTAIN  A  5  BY  7  REFLECTING  CAMERA  WHEN  USED  UNDER  WATER. 


For  description  see  text,  page  6'J. 


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